Phenolic guanidine sodium channel blockers

ABSTRACT

The present invention relates to sodium channel blockers. The present invention also relates to a variety of methods of treatment using these sodium channel blockers.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to sodium channel blockers. Thepresent invention also includes a variety of methods of treatment usingthese inventive sodium channel blockers.

[0003] 2. Description of the Background

[0004] The mucosal surfaces at the interface between the environment andthe body have evolved a number of “innate defense”, i.e., protectivemechanisms. A principal form of such innate defense is to cleanse thesesurfaces with liquid. Typically, the quantity of the liquid layer on amucosal surface reflects the balance between epithelial liquidsecretion, often reflecting anion (Cl⁻ and/or HCO₃ ⁻) secretion coupledwith water (and a cation counter-ion), and epithelial liquid absorption,often reflecting Na⁺ absorption, coupled with water and counter anion(Cl⁻ and/or HCO₃ ⁻). Many diseases of mucosal surfaces are caused by toolittle protective liquid on those mucosal surfaces created by animbalance between secretion (too little) and absorption (relatively toomuch). The defective salt transport processes that characterize thesemucosal dysfunctions reside in the epithelial layer of the mucosalsurface.

[0005] One approach to replenish the protective liquid layer on mucosalsurfaces is to “re-balance” the system by blocking Na⁺ channel andliquid absorption. The epithelial protein that mediates therate-limiting step of Na⁺ and liquid absorption is the epithelial Na⁺channel (ENaC). ENaC is positioned on the apical surface of theepithelium, i.e. the mucosal surface-environmental interface. Therefore,to inhibit ENaC mediated Na⁺ and liquid absorption, an ENaC blocker ofthe amiloride class (which blocks from the extracellular domain of ENaC)must be delivered to the mucosal surface and, importantly, be maintainedat this site, to achieve therapeutic utility. The present inventiondescribes diseases characterized by too little liquid on mucosalsurfaces and “topical” sodium channel blockers designed to exhibit theincreased potency, reduced mucosal absorption, and slow dissociation(“unbinding” or detachment) from ENaC required for therapy of thesediseases.

[0006] Chronic bronchitis (CB), including the most common lethal geneticform of chronic bronchitis, cystic fibrosis (CF), are diseases thatreflect the body's failure to clear mucus normally from the lungs, whichultimately produces chronic airways infection. In the normal lung, theprimary defense against chronic intrapulmonary airways infection(chronic bronchitis) is mediated by the continuous clearance of mucusfrom bronchial airway surfaces. This function in health effectivelyremoves from the lung potentially noxious toxins and pathogens. Recentdata indicate that the initiating problem, i.e., the “basic defect,” inboth CB and CF is the failure to clear mucus from airway surfaces. Thefailure to clear mucus reflects an imbalance between the amount ofliquid and mucin on airway surfaces. This “airway surface liquid” (ASL)is primarily composed of salt and water in proportions similar to plasma(i.e., isotonic). Mucin macromolecules organize into a well defined“mucus layer” which normally traps inhaled bacteria and is transportedout of the lung via the actions of cilia which beat in a watery, lowviscosity solution termed the “periciliary liquid” (PCL). In the diseasestate, there is an imbalance in the quantities of mucus as ASL on airwaysurfaces. This results in a relative reduction in ASL which leads tomucus concentration, reduction in the lubricant activity of the PCL, anda failure to clear mucus via ciliary activity to the mouth. Thereduction in mechanical clearance of mucus from the lung leads tochronic bacterial colonization of mucus adherent to airway surfaces. Itis the chronic retention of bacteria, the failure of local antimicrobialsubstances to kill mucus-entrapped bacteria on a chronic basis, and theconsequent chronic inflammatory responses of the body to this type ofsurface infection, that lead to the syndromes of CB and CF.

[0007] The current afflicted population in the U.S. is 12,000,000patients with the acquired (primarily from cigarette smoke exposure)form of chronic bronchitis and approximately 30,000 patients with thegenetic form, cystic fibrosis. Approximately equal numbers of bothpopulations are present in Europe. In Asia, there is little CF but theincidence of CB is high and, like the rest of the world, is increasing.

[0008] There is currently a large, unmet medical need for products thatspecifically treat CB and CF at the level of the basic defect that causethese diseases. The current therapies for chronic bronchitis and cysticfibrosis focus on treating the symptoms and/or the late effects of thesediseases. Thus, for chronic bronchitis, β-agonists, inhaled steroids,anti-cholinergic agents, and oral theophyllines and phosphodiesteraseinhibitors are all in development. However, none of these drugs treateffectively the fundamental problem of the failure to clear mucus fromthe lung. Similarly, in cystic fibrosis, the same spectrum ofpharmacologic agents is used. These strategies have been complemented bymore recent strategies designed to clear the CF lung of the DNA(“Pulmozyme”; Genentech) that has been deposited in the lung byneutrophils that have futilely attempted to kill the bacteria that growin adherent mucus masses and through the use of inhaled antibiotics(“TOBI”) designed to augment the lungs' own killing mechanisms to ridthe adherent mucus plaques of bacteria. A general principle of the bodyis that if the initiating lesion is not treated, in this case mucusretention/obstruction, bacterial infections became chronic andincreasingly refractory to antimicrobial therapy. Thus, a major unmettherapeutic need for both CB and CF lung diseases is an effective meansof re-hydrating airway mucus (i.e., restoring/expanding the volume ofthe ASL) and promoting its clearance, with bacteria, from the lung.

[0009] R. C. Boucher, in U.S. Pat. No. 6,264,975, describes the use ofpyrazinoylguanidine sodium channel blockers for hydrating mucosalsurfaces. These compounds, typified by the well-known diureticsamiloride, benzamil, and phenamil, are effective. However, thesecompounds suffer from the significant disadvantage that they are (1)relatively impotent, which is important because the mass of drug thatcan be inhaled by the lung is limited; (2) rapidly absorbed, whichlimits the half-life of the drug on the mucosal surface; and (3) arefreely dissociable from ENaC. The sum of these disadvantages embodied inthese well known diurectics produces compounds with insufficient potencyand/or effective half-life on mucosal surfaces to have therapeuticbenefit for hydrating mucosal surfaces.

[0010] Clearly, what is needed are drugs that are more effective atrestoring the clearance of mucus from the lungs of patients with CB/CF.The value of these new therapies will be reflected in improvements inthe quality and duration of life for both the CF and the CB populations.

[0011] Other mucosal surfaces in and one the body exhibit subtledifferences in the normal physiology of the protective surface liquidson their surfaces but the pathophysiology of disease reflects a commontheme, i.e., too little protective surface liquid. For example, inxerostomia (dry mouth) the oral cavity is depleted of liquid due to afailure of the parotid sublingual and submandibular glands to secreteliquid despite continued Na⁺ (ENaC) transport mediated liquid absorptionfrom the oral cavity. Similarly, keratoconjunctivitis sira (dry eye) iscaused by failure of lacrimal glands to secrete liquid in the face ofcontinued Na⁺ dependent liquid absorption on conjunctional surfaces. Inrhinosinusitis, there is an imbalance, as in CB, between mucin secretionand relative ASL depletion. Finally, in the gastrointestinal tract,failure to secrete Cl⁻ (and liquid) in the proximal small intestine,combined with increased Na⁺ (and liquid) absorption in the terminalileum leads to the distal intestinal obstruction syndrome (DIOS). Inolder patients excessive Na⁺ (and volume) absorption in the descendingcolon produces constipation and diverticulitis.

SUMMARY OF THE INVENTION

[0012] It is an object of the present invention to provide compoundsthat are more potent and/or absorbed less rapidly from mucosal surfaces,and/or are less reversible as compared to known compounds.

[0013] It is another aspect of the present invention to providecompounds of formula (I) that are more potent and/or absorbed lessrapidly and/or exhibit less reversibility, as compared to compounds suchas amilorde, benzamil, and phenamil. Therefore, the compounds of formula(I) will give a prolonged pharmacodynamic half-life on mucosal surfacesas compared to known compounds.

[0014] It is another object of the present invention to providecompounds of formula (I) which are (1) absorbed less rapidly frommucosal surfaces, especially airway surfaces, as compared to knowncompounds and; (2) when absorbed from mucosal surfaces afteradministration to the mucosal surfaces, are converted in vivo intometabolic derivatives thereof which have reduced efficacy in blockingsodium channels as compared to the administered parent compound.

[0015] It is another object of the present invention to providecompounds of formula (I) that are more potent and/or absorbed lessrapidly and/or exhibit less reversibility, as compared to compounds suchas amiloride, benzamil, and phenamil. Therefore, the compounds offormula (I) will give a prolonged pharmacodynamic half-life on mucosalsurfaces as compared to previous compounds.

[0016] It is another object of the present invention to provide methodsof treatment which take advantage of the properties described above.

[0017] The objects of the present invention may be accomplished with aclass of pyrazinoylguanidine compounds represented by a compoundrepresented by formula (I):

[0018] wherein

[0019] X is hydrogen, halogen, trifluoromethyl, lower alkyl,unsubstituted or substituted phenyl, lower alkyl-thio, phenyl-loweralkyl-thio, lower alkyl-sulfonyl, or phenyl-lower alkyl-sulfonyl;

[0020] Y is hydrogen, hydroxyl, mercapto, lower alkoxy, loweralkyl-thio, halogen, lower alkyl, unsubstituted or substitutedmononuclear aryl, or —N(R²)₂;

[0021] R¹ is hydrogen or lower alkyl;

[0022] each R² is, independently, —R⁷, —(CH₂)_(m)—OR⁸,—(CH₂)_(m)—NR⁷R¹⁰, —(CH₂)_(n)(CHOR⁸)(CHOR⁸)_(n)—CH₂OR⁸,—(CH₂CH₂O)_(m)—R⁸, —(CH₂CH₂O)_(m)—CH₂CH₂NR⁷R¹⁰, —(CH₂)_(n)—C(═O)NR⁷R¹⁰,—(CH₂)_(n)-Z_(g)-R⁷, —(CH₂)_(m)—NR¹⁰—CH₂(CHOR⁸)(CHOR⁸)_(n)—CH₂OR⁸,—(CH₂)_(n)—CO₂R⁷, or

[0023] R³ and R⁴ are each, independently, hydrogen, a group representedby formula (A), lower alkyl, hydroxy lower alkyl, phenyl, phenyl-loweralkyl, (halophenyl)-lower alkyl, lower-(alkylphenylalkyl), loweralkoxyphenyl)-lower alkyl, naphthyl-lower alkyl, or pyridyl-lower alkyl,with the proviso that at least one of R³ and R⁴ is a group representedby formula (A):

[0024] wherein

[0025] each R^(L) is, independently, —R⁷, —(CH₂)_(n)—OR⁸,—O—(CH₂)_(m)—OR⁸, —(CH₂)_(n)—NR⁷R¹⁰, —O—(CH₂)_(m)—NR⁷R¹⁰,—(CH₂)_(n)(CHOR⁸)(CHOR⁸)_(n)—CH₂OR⁸,—O—(CH₂)_(m)(CHOR⁸)(CHOR⁸)_(n)—CH₂OR⁸, —(CH₂CH₂O)_(m)—R⁸,—O—(CH₂CH₂O)_(m)—R⁸, —(CH₂CH₂O)_(m)—CH₂CH₂NR⁷R¹⁰,—O—(CH₂CH₂O)_(m)—CH₂CH₂NR⁷R¹⁰, —(CH₂)_(n)—C(═O)NR⁷R¹⁰,—O—(CH₂)_(m)—C(═O)NR⁷R¹⁰, —(CH₂)_(n)-(Z)_(g)-R⁷,—O—(CH₂)_(m)-(Z)_(g)-R⁷, —(CH₂)_(n)—NR¹⁰—CH₂(CHOR⁸)(CHOR⁸)_(n)—CH₂OR⁸,—O—(CH₂)_(m)—NR¹⁰—CH₂(CHOR⁸)(CHOR⁸)_(n)—CH₂OR⁸, —(CH₂)_(n)—CO₂R⁷,—O—(CH₂)_(m)—CO₂R⁷, —OSO₃H, —O-glucuronide, —O-glucose, or

[0026] each x is, independently, O, NR⁷, C═O, CHOH, C═N—R⁶, orrepresents a single bond;

[0027] each o is, independently, an integer from 0 to 10;

[0028] each p is, independently, an integer from 0 to 10;

[0029] with the proviso that (a) the sum of o and p in each contiguouschain is from 1 to 10 when x is O, NR⁷, C═O, or C═N—R⁶ or (b) that thesum of o and p in each contiguous chain is from 4 to 10 when xrepresents a single bond;

[0030] each R⁶ is, independently, —R⁷, —OH, —OR¹¹, —N(R⁷)₂,—(CH₂)_(m)—OR⁸, —O—(CH₂)_(m)—OR⁸, —(CH₂)_(n)—NR⁷R¹⁰,—O—(CH₂)_(m)—NR⁷R¹⁰, —(CH₂)_(n)(CHOR⁸)(CHOR⁸)_(n)—CH₂OR⁸,—O—(CH₂)_(m)(CHOR⁸)(CHOR⁸)_(n)—CH₂OR⁸, —(CH₂CH₂O)_(m)—R⁸,—O—(CH₂CH₂O)_(m)—R⁸, —(CH₂CH₂O)_(m)—CH₂CH₂NR⁷R¹⁰,—O—(CH₂CH₂O)_(m)—CH₂CH₂NR⁷R¹⁰, —(CH₂)_(n)—C(═O)NR⁷R¹⁰,—O—(CH₂)_(m)—C(═O)NR⁷R¹⁰, —(CH₂)_(n)-(Z)_(g)-R⁷,—O—(CH₂)_(m)-(Z)_(g)-R⁷, —(CH₂)_(n)—NR¹⁰—CH₂(CHOR⁸)(CHOR⁸)_(n)—CH₂OR⁸,—O—(CH₂)_(m)—NR¹⁰—CH₂(CHOR⁸)(CHOR⁸)_(n)—CH₂OR⁸, —(CH₂)_(n)—CO₂R⁷,—O—(CH₂)_(m)—CO₂R⁷, —OSO₃H, —O-glucuronide, —O-glucose,

[0031] wherein when two R⁶ are —OR¹¹ and are located adjacent to eachother on a phenyl ring, the alkyl moieties of the two R⁶ may be bondedtogether to form a methylenedioxy group;

[0032] each R⁷ is, independently, hydrogen or lower alkyl;

[0033] each R⁸ is, independently, hydrogen, lower alkyl, —C(═O)—R¹¹,glucuronide, 2-tetrahydropyranyl, or

[0034] each R⁹ is, independently, —CO₂R⁷, —CON(R⁷)₂, —SO₂CH₃, or—C(═O)R⁷;

[0035] each R¹⁰ is, independently, —H, —SO₂CH₃, —CO₂R⁷, —C(═O)NR⁷R⁹,—C(═O)R⁷, or —CH₂—(CHOH)_(n)—CH₂OH;

[0036] each Z is, independently, CHOH, C(═O), CHNR⁷R¹⁰, C═NR¹⁰, or NR¹⁰;

[0037] each R¹¹ is, independently, lower alkyl;

[0038] each g is, independently, an integer from 1 to 6;

[0039] each m is, independently, an integer from 1 to 7;

[0040] each n is, independently, an integer from 0 to 7;

[0041] each Q is, independently, C—R⁵, C—R⁶, or a nitrogen atom, whereinat

[0042] most three Q in a ring are nitrogen atoms;

[0043] or a pharmaceutically acceptable salt thereof, and

[0044] inclusive of all enantiomers, diastereomers, and racemic mixturesthereof.

[0045] The present also provides pharmaceutical compositions whichcontain a compound represented above.

[0046] The present invention also provides a method of promotinghydration of mucosal surfaces, comprising:

[0047] administering an effective amount of a compound represented byformula (I) to a mucosal surface of a subject.

[0048] The present invention also provides a method of restoring mucosaldefense, comprising:

[0049] topically administering an effective amount of compoundrepresented by formula (I) to a mucosal surface of a subject in needthereof.

[0050] The present invention also provides a method of blocking ENaC,comprising:

[0051] contacting sodium channels with an effective amount of a compoundrepresented by formula (I).

[0052] The present invention also provides a method of promoting mucusclearance in mucosal surfaces, comprising:

[0053] administering an effective amount of a compound represented byformula (I) to a mucosal surface of a subject.

[0054] The present invention also provides a method of treating chronicbronchitis, comprising:

[0055] administering an effective amount of a compound represented byformula (I) to a subject in need thereof.

[0056] The present invention also provides a method of treating cysticfibrosis, comprising:

[0057] administering an effective amount of compound represented byformula (I) to a subject in need thereof.

[0058] The present invention also provides a method of treatingrhinosinusitis, comprising:

[0059] administering an effective amount of a compound represented by aformula (I) to a subject in need thereof.

[0060] The present invention also provides a method of treating nasaldehydration, comprising:

[0061] administering an effective amount of a compound represented byformula (I) to the nasal passages of a subject in need thereof.

[0062] The present invention also provides a method of treating nasaldehydration, where the nasal dehydration is brought on by administeringdry oxygen to the subject.

[0063] The present invention also provides a method of treatingsinusitis, comprising:

[0064] administering an effective amount of a compound represented byformula (I) to a subject in need thereof.

[0065] The present invention also provides a method of-treatingpneumonia, comprising:

[0066] administering an effective amount of a compound represented byformula (I) to a subject in need thereof.

[0067] The present invention also provides a method of preventingventilator-induced pneumonia, comprising:

[0068] administering an effective compound represented by formula (I) toa subject by means of a ventilator.

[0069] The present invention also provides a method of treating asthma,comprising:

[0070] administering an effective amount of a compound represented byformula (I) to a subject in need thereof.

[0071] The present invention also provides a method of treating primaryciliary dyskinesia, comprising:

[0072] administering an effective amount of a compound represented byformula (I) to a subject in need thereof.

[0073] The present invention also provides a method of treating otitismedia, comprising:

[0074] administering an effective amount of a compound represented byformula (I) to a subject in need thereof.

[0075] The present invention also provides a method of inducing sputumfor diagnostic purposes, comprising:

[0076] administering an effective amount of compound represented byformula (I) to a subject in need thereof.

[0077] The present invention also provides a method of treating chronicobstructive pulmonary disease, comprising:

[0078] administering an effective amount of a compound represented byformula (I) to a subject in need thereof.

[0079] The present invention also provides a method of treatingemphysema, comprising:

[0080] administering an effective amount of a compound represented byformula (I) to a subject in need thereof.

[0081] The present invention also provides a method of treating dry eye,comprising:

[0082] administering an effective amount of a compound represented byformula (I) to the eye of the subject in need thereof.

[0083] The present invention also provides a method of promoting ocularhydration, comprising:

[0084] administering an effective amount of a compound represented byformula (I) to the eye of the subject.

[0085] The present invention also provides a method of promoting cornealhydration, comprising:

[0086] administering an effective amount of a compound represented byformula (I) to the eye of the subject.

[0087] The present invention also provides a method of treatingSjögren's disease, comprising:

[0088] administering an effective amount of compound represented byformula (I) to a subject in need thereof.

[0089] The present invention also provides a method of treating vaginaldryness, comprising:

[0090] administering an effective amount of a compound represented byformula (I) to the vaginal tract of a subject in need thereof.

[0091] The present invention also provides a method of treating dryskin, comprising:

[0092] administering an effective amount of a compound represented byformula (I) to the skin of a subject in need thereof.

[0093] The present invention also provides a method of treating drymouth (xerostomia), comprising:

[0094] administering an effective amount of compound represented byformula (I) to the mouth of the subject in need thereof.

[0095] The present invention also provides a method of treating distalintestinal obstruction syndrome, comprising:

[0096] administering an effective amount of compound represented byformula (I) to a subject in need thereof.

[0097] The present invention also provides a method of treatingesophagitis, comprising:

[0098] administering an effective amount of a compound represented byformula (I) to a subject in need thereof.

[0099] The present invention also provides a method of treatingconstipation, comprising:

[0100] administering an effective amount of a compound represented byformula (I) to a subject in need thereof. In one embodiment of thismethod, the compound is administered either orally or via a suppositoryor enema.

[0101] The present invention also provides a method of treating chronicdiverticulitis comprising:

[0102] administering an effective amount of a compound represented byformula (I) to a subject in need thereof.

BRIEF DESCRIPTION OF THE FIGURES

[0103] A more complete appreciation of the invention and many of theattendant advantages thereof will be readily obtained as the samebecomes better understood by reference to the following detaileddescription considered in conjunction with the following figures:

[0104]FIG. 1: Effect of a compound of the present invention on MCC att=0 hrs as described in Example 9 herein.

[0105]FIG. 2: Effect of a compound of the present invention on MCC att=4 hrs as described in Example 9 herein.

DETAILED DESCRIPTION OF THE INVENTION

[0106] The present invention is based on the discovery that thecompounds of formula (I) are more potent and/or, absorbed less rapidlyfrom mucosal surfaces, especially airway surfaces, and/or lessreversable from interactions with ENaC as compared to compounds such asamiloride, benzamil, and phenamil. Therefore, the compounds of formulahave a higher half-life on mucosal surfaces as compared to thesecompounds.

[0107] The present invention is also based on the discover that certaincompounds embraced by formula (I) are converted in vivo into metabolicderivatives thereof which have reduced efficacy in blocking sodiumchannels as compared to the parent administered compound, after they areabsorbed form mucosal surfaces after administration. This importantproperty means that the compounds will have a lower tendency to causeundesired side-effects by blocking sodium channels located at untargetedlocations in the body of the recipient, e.g., in the kidneys.

[0108] In the compounds represented by formula (I), X may be hydrogen,halogen, trifluoromethyl, lower alkyl, lower cycloalkyl, unsubstitutedor substituted phenyl, lower alkyl-thio, phenyl-lower alkyl-thio, loweralkyl-sulfonyl, or phenyl-lower alkyl-sulfonyl. Halogen is preferred.

[0109] Examples of halogen include fluorine, chlorine, bromine, andiodine. Chlorine and bromine are the preferred halogens. Chlorine isparticularly preferred. This description is applicable to the term“halogen” as used throughout the present disclosure.

[0110] As used herein, the term “lower alkyl” means an alkyl grouphaving less than 8 carbon atoms. This range includes all specific valuesof carbon atoms and subranges therebetween, such as 1, 2, 3, 4, 5, 6,and 7 carbon atoms. The term “alkyl” embraces all types of such groups,e.g., linear, branched, and cyclic alkyl groups. This description isapplicable to the term “lower alkyl” as used throughout the presentdisclosure. Example of suitable lower alkyl groups include methyl,ethyl, propyl, cyclopropyl, butyl, isobutyl, etc.

[0111] Substituents for the phenyl group include halogens. Particularlypreferred halogen substituents are chlorine and bromine.

[0112] Y may be hydrogen, hydroxyl, mercapto, lower alkoxy, loweralkyl-thio, halogen, lower alkyl, lower cycloalkyl, mononuclear aryl, or—N(R²)₂. The alkyl moiety of the lower alkoxy groups is the same asdescribed above. Examples of mononuclear aryl include phenyl groups. Thephenyl group may be unsubstituted or substituted as described above. Thepreferred identity of Y is —N(R²)₂. Particularly preferred are suchcompounds where each R² is hydrogen.

[0113] R¹ may be hydrogen or lower alkyl. Hydrogen is preferred for R¹.

[0114] Each R² may be, independently, —R⁷, —(CH₂)_(m)—OR⁸,—(CH₂)_(m)—NR⁷R¹⁰, —(CH₂)_(n)(CHOR⁸)(CHOR⁸)_(n)—CH₂OR⁸,—(CH₂CH₂O)_(m)—R⁸, —(CH₂CH₂O)_(m)—CH₂CH₂NR⁷R¹⁰, —(CH₂)_(n)—C(═O)NR⁷R¹⁰,—(CH₂)_(n)-Z_(g)-R⁷, —(CH₂)_(m)—NR¹⁰—CH₂(CHOR⁸)(CHOR⁸)_(n)—CH₂OR⁸,—(CH₂)_(n)—CO₂R⁷, or

[0115] Hydrogen and lower alkyl, particularly C₁-C₃ alkyl are preferredfor R². Hydrogen is particularly preferred.

[0116] R³ and R⁴ may be, independently, hydrogen, a group represented byformula (A), lower alkyl, hydroxy lower alkyl, phenyl, phenyl-loweralkyl, (halophenyl)-lower alkyl, lower-(alkylphenylalkyl), lower(alkoxyphenyl)-lower alkyl, naphthyl-lower alkyl, or pyridyl-loweralkyl, provided that at least one of R³ and R⁴ is a group represented byformula (A).

[0117] Preferred compounds are those where one of R³ and R⁴ is hydrogenand the other is represented by formula (A).

[0118] In formula (A), the moiety —(C(R^(L))₂)_(o)-x-(C(R^(L))₂)_(p)—defines an alkylene group bonded to the aromatic ring. The variables oand p may each be an integer from 0 to 10, subject to the proviso thatthe sum of o and p in the chain is from 1 to 10. Thus, o and p may eachbe 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10. Preferably, the sum of o and pis from 2 to 6. In a particularly preferred embodiment, the sum of o andp is 4.

[0119] The linking group in the alkylene chain, x, may be,independently, O, NR¹⁰, C(═O), CHOH, C(═N—R¹⁰), CHNR⁷R¹⁰, or representsa single bond;

[0120] Therefore, when x represents a single bond, the alkylene chainbonded to the ring is represented by the formula —(C(R^(L))₂)_(o+p)—, inwhich the sum o+p is from 1 to 10.

[0121] Each R^(L) may be, independently, —R⁷, —(CH₂)_(n)—OR⁸,—O—(CH₂)_(m)—OR⁸, —(CH₂)_(n)—NR⁷R¹⁰, —O—(CH₂)_(m)—NR⁷R¹⁰,—(CH₂)_(n)(CHOR⁸)(CHOR⁸)_(n)—CH₂OR⁸,—O—(CH₂)_(m)(CHOR⁸)(CHOR⁸)_(n)—CH₂OR⁸, —(CH₂CH₂O)_(m)—R⁸,—O—(CH₂CH₂O)_(m)—R⁸, —(CH₂CH₂O)_(m)—CH₂CH₂NR⁷R¹⁰,—O—(CH₂CH₂O)_(m)—CH₂CH₂NR⁷R¹⁰, —(CH₂)_(n)—C(═O)NR⁷R¹⁰,—O—(CH₂)_(m)—C(═O)NR⁷R¹⁰, —(CH₂)_(n)-(Z)_(g)-R⁷,—O—(CH₂)_(m)-(Z)_(g)-R⁷, —(CH₂)_(n)—NR¹⁰—CH₂(CHOR⁸)(CHOR⁸)_(n)—CH₂OR⁸,—O—(CH₂)_(m)—NR¹⁰—CH₂(CHOR⁸)(CHOR⁸)_(n)—CH₂OR⁸, —(CH₂)_(n)—CO₂R⁷,—O—(CH₂)_(m)—CO₂R⁷, —OSO₃H, —O-glucuronide, —O-glucose, or

[0122] The preferred R^(L) groups include —H, —OH, —N(R⁷)₂, especiallywhere each R⁷ is hydrogen.

[0123] In the alkylene chain in formula (A), it is preferred that whenone R^(L) group bonded to a carbon atoms is other than hydrogen, thenthe other R^(L) bonded to that carbon atom is hydrogen, i.e., theformula —CHR^(L)—. It is also preferred that at most two R^(L) groups inan alkylene chain are other than hydrogen, where in the other R^(L)groups in the chain are hydrogens. Even more preferably, only one R^(L)group in an alkylene chain is other than hydrogen, where in the otherR^(L) groups in the chain are hydrogens. In these embodiments, it ispreferable that x represents a single bond.

[0124] In another particular embodiment of the invention, all of theR^(L) groups in the alkylene chain are hydrogen. In these embodiments,the alkylene chain is represented by the formula—(CH₂)_(o)-x-(CH₂)_(p)—.

[0125] There are four R⁶ groups present on the ring in formula (A). EachR⁶ may be each, independently, —R⁷, —OH, —OR¹¹, —N(R⁷)₂, —(CH₂)_(m)—OR⁸,—O—(CH₂)_(m)—OR⁸, —(CH₂)_(n)—NR⁷R¹⁰, —O—(CH₂)_(m)—NR⁷R¹⁰,—(CH₂)_(n)(CHOR⁸)(CHOR⁸)_(n)—CH₂OR⁸,—O—(CH₂)_(m)(CHOR⁸)(CHOR⁸)_(n)—CH₂OR⁸, —(CH₂CH₂O)_(m)—R⁸,—O—(CH₂CH₂O)_(m)R⁸, —(CH₂CH₂O)_(m)—CH₂CH₂NR⁷R¹⁰,—O—(CH₂CH₂O)_(m)—CH₂CH₂NR⁷R¹⁰, —(CH₂)_(n)—C(═O)NR⁷R¹⁰,—O—(CH₂)_(m)—C(═O)NR⁷R¹⁰, —(CH₂)_(n)-(Z)_(g)-R⁷,—O—(CH₂)_(m)-(Z)_(g)-R⁷, —(CH₂)_(n)—NR¹⁰—CH₂(CHOR⁸)(CHOR⁸)_(n)—CH₂OR⁸,—O—(CH₂)_(m)—NR¹⁰—CH₂(CHOR⁸)(CHOR⁸)_(n)—CH₂OR⁸, —(CH₂)_(n)—CO₂R⁷,—O—(CH₂)_(m)—CO₂R⁷, —OSO₃H, —O-glucuronide, —O-glucose,

[0126] When two R⁶ are —OR¹¹ and are located adjacent to each other on aphenyl ring, the alkyl moieties of the two R⁶ groups may be bondedtogether to form a methylenedioxy group, i.e., a group of the formula—O—CH₂—O—.

[0127] As discussed above, R⁶ may be hydrogen. Therefore, 1, 2, 3, or 4R⁶ groups may be other than hydrogen. Preferably at most 3 of the R⁶groups are other than hydrogen.

[0128] Each g is, independently, an integer from 1 to 6. Therefore, eachg may be 1, 2, 3, 4, 5, or 6.

[0129] Each m is an integer from 1 to 7. Therefore, each m may be 1, 2,3, 4, 5, 6, or 7.

[0130] Each n is an integer from 0 to 7. Therefore, each n maybe 0, 1,2, 3, 4, 5, 6, or 7.

[0131] Each Q in formula (A) is C—R⁵, C—R⁶, or a nitrogen atom, where atmost three Q in a ring are nitrogen atoms. Thus, there may be 1, 2, or 3nitrogen atoms in a ring. Preferably, at most two Q are nitrogen atoms.More preferably, at most one Q is a nitrogen atom. In one particularembodiment, the nitrogen atom is at the 3-position of the ring. Inanother embodiment of the invention, each Q is either C—R⁵ or C—R⁶,i.e., there are no nitrogen atoms in the ring.

[0132] In a preferred embodiment of the present invention:

[0133] X is halogen;

[0134] Y is —N(R⁷)₂;

[0135] R¹ is hydrogen or C₁-C₃ alkyl; —(CH₂)_(n)—CO₂R⁷;

[0136] R² is —R⁷, —(CH₂)_(m)—OR⁷, or —CO₂R⁷;

[0137] R³ is a group represented by formula (A); and

[0138] R⁴ is hydrogen, a group represented by formula (A), or loweralkyl;

[0139] In another preferred embodiment of the present invention:

[0140] X is chloro or bromo;

[0141] Y is —N(R⁷)₂;

[0142] R² is hydrogen or C₁-C₃ alkyl;

[0143] at most three R⁶ are other than hydrogen as described above;

[0144] at most three R^(L) are other than hydrogen as described above;and

[0145] at most 2 Q are nitrogen atoms.

[0146] In another preferred embodiment of the present invention:

[0147] Y is —NH₂.

[0148] In another preferred embodiment of the present invention:

[0149] R⁴ is hydrogen;

[0150] at most one R^(L) is other than hydrogen as described above;

[0151] at most two R⁶ are other than hydrogen as described above; and

[0152] at most 1 Q is a nitrogen atom.

[0153] In another preferred embodiment of the present invention, x is O,NR⁷, C═O, CHOH, or C═N—R⁶. In another preferred embodiment of thepresent invention, x represents a single bond.

[0154] In another preferred embodiment of the present invention, each R⁶is hydrogen. In another preferred embodiment of the present invention,at most two R⁶ are other than hydrogen as described above. In anotherpreferred embodiment of the present invention, one R⁶ is other thanhydrogen as described above. In another preferred embodiment of thepresent invention, one R⁶ is —OH.

[0155] In another preferred embodiment of the present invention, eachR^(L) is hydrogen. In another preferred embodiment of the presentinvention, at most two R^(L) are other than hydrogen as described above.In another preferred embodiment of the present invention, one R^(L) isother than hydrogen as described above.

[0156] In another preferred embodiment of the present invention, xrepresents a single bond and the sum of o and p is 4 to 6.

[0157] In another preferred embodiment of the present invention thecompound of formula (I) is represented by the formula:

[0158] In another preferred embodiment of the present invention thecompound of formula (I) is represented by the formula:

[0159] In another preferred embodiment of the present invention thecompound of formula (I) is represented by the formula:

[0160] In another preferred embodiment of the present invention thecompound of formula (I) is represented by the formula:

[0161] In another preferred embodiment of the present invention thecompound of formula (I) is represented by the formula:

[0162] In another preferred embodiment of the present invention thecompound of formula (I) is represented by the formula:

[0163] The compounds of formula (I) may be prepared and used as the freebase. Alternatively, the compounds may be prepared and used as apharmaceutically acceptable salt. Pharmaceutically acceptable salts aresalts that retain or enhance the desired biological activity of theparent compound and do not impart undesired toxicological effects.Examples of such salts are (a) acid addition salts formed with inorganicacids, for example, hydrochloric acid, hydrobromic acid, sulfuric acid,phosphoric acid, nitric acid and the like; (b) salts formed with organicacids such as, for example, acetic acid, oxalic acid, tartaric acid,succinic acid, maleic acid, fumaric acid, gluconic acid, citric acid,malic acid, ascorbic acid, benzoic acid, tannic acid, palmitic acid,alginic acid, polyglutamic acid, naphthalenesulfonic acid,methanesulfonic acid, p-toluenesulfonic acid, naphthalenedisulfonicacid, polygalacturonic acid, malonic acid, sulfosalicylic acid,,glycolic acid, 2-hydroxy-3-naphthoate, pamoate, salicylic acid, stearicacid, phthalic acid, mandelic acid, lactic acid and the like; and (c)salts formed from elemental anions for example, chlorine, bromine, andiodine.

[0164] It is to be noted that all enantiomers, diastereomers, andracemic mixtures of compounds within the scope of formula (I) areembraced by the present invention. All mixtures of such enantiomers anddiastereomers are within the scope of the present invention.

[0165] Without being limited to any particular theory, it is believedthat the compounds of formula (I) function in vivo as sodium channelblockers. By blocking epithelial sodium channels present in mucosalsurfaces the compounds of formula (I) reduce the absorption of water bythe mucosal surfaces. This effect increases the volume of protectiveliquids on mucosal surfaces, rebalances the system, and thus treatsdisease.

[0166] The present invention also provides methods of treatment thattake advantage of the properties of the compounds of formula (I)discussed above. Thus, subjects that may be treated by the methods ofthe present invention include, but are not limited to, patientsafflicted with cystic fibrosis, primary ciliary dyskinesia, chronicbronchitis, chronic obstructive airway disease, artificially ventilatedpatients, patients with acute pneumonia, etc. The present invention maybe used to obtain a sputum sample from a patient by administering theactive compounds to at least one lung of a patient, and then inducing orcollecting a sputum sample from that patient. Typically, the inventionwill be administered to respiratory mucosal surfaces via aerosol (liquidor dry powders) or lavage.

[0167] Subjects that may be treated by the method of the presentinvention also include patients being administered supplemental oxygennasally (a regimen that tends to dry the airway surfaces); patientsafflicted with an allergic disease or response (e.g., an allergicresponse to pollen, dust, animal hair or particles, insects or insectparticles, etc.) that affects nasal airway surfaces; patients afflictedwith a bacterial infection e.g., staphylococcus infections such asStaphylococcus aureus infections, Hemophilus influenza infections,Streptococcus pneumoniae infections, Pseudomonas aeuriginosa infections,etc.) of the nasal airway surfaces; patients afflicted with aninflammatory disease that affects nasal airway surfaces; or patientsafflicted with sinusitis (wherein the active agent or agents areadministered to promote drainage of congested mucous secretions in thesinuses by administering an amount effective to promote drainage ofcongested fluid in the sinuses), or combined, Rhinosinusitis. Theinvention may be administered to rhino-sinal surfaces by topicaldelivery, including aerosols and drops.

[0168] The present invention may be used to hydrate mucosal surfacesother than airway surfaces. Such other mucosal surfaces includegastrointestinal surfaces, oral surfaces, genito-urethral surfaces,ocular surfaces or surfaces of the eye, the inner ear and the middleear. For example, the active compounds of the present invention may beadministered by any suitable means, including locally/topically, orally,or rectally, in an effective amount.

[0169] The present invention is concerned primarily with the treatmentof human subjects, but may also be employed for the treatment of othermammalian subjects, such as dogs and cats, for veterinary purposes.

[0170] As discussed above, the compounds used to prepare thecompositions of the present invention may be in the form of apharmaceutically acceptable free base. Because the free base of thecompound is generally less soluble in aqueous solutions than the salt,free base compositions are employed to provide more sustained release ofactive agent to the lungs. An active agent present in the lungs inparticulate form which has not dissolved into solution is not availableto induce a physiological response, but serves as a depot ofbioavailable drug which gradually dissolves into solution.

[0171] Another aspect of the present invention is a pharmaceuticalcomposition, comprising a compound of formula (I) in a pharmaceuticallyacceptable carrier (e.g., an aqueous carrier solution). In general, thecompound of formula (I) is included in the composition in an amounteffective to inhibit the reabsorption of water by mucosal surfaces.

[0172] The compounds of the present invention may also be used inconjunction with a P2Y2 receptor agonist or a pharmaceuticallyacceptable salt thereof (also sometimes referred to as an “active agent”herein). The composition may further comprise a P2Y2 receptor agonist ora pharmaceutically acceptable salt thereof (also sometimes referred toas an “active agent” herein). The P2Y2 receptor agonist is typicallyincluded in an amount effective to stimulate chloride and watersecretion by airway surfaces, particularly nasal airway surfaces.Suitable P2Y2 receptor agonists are described in columns 9-10 of U.S.Pat. No. 6,264,975, U.S. Pat. No. 5,656,256, and U.S. Pat. No.5,292,498, each of which is incorporated herein by reference.

[0173] Bronchodiloators can also be used in combination with compoundsof the present invention. These Bronchodilators include, but are notlimited to, β-adrenergic agonists including but not limited toepinephrine, isoproterenol, fenoterol, albutereol, terbutalin,pirbuterol, bitolterol, metaproterenol, iosetharine, salmeterolxinafoate, as well as anticholinergic agents including but not limitedto ipratropium bromide, as well as compounds such as theophylline andaminophylline. These compounds may be administered in accordance withknown techniques, either prior to or concurrently with the activecompounds described herein.

[0174] Another aspect of the present invention is a pharmaceuticalformulation, comprising an active compound as described above in apharmaceutically acceptable carrier (e.g., an aqueous carrier solution).In general, the active compound is included in the composition in anamount effective to treat mucosal surfaces, such as inhibiting thereabsorption of water by mucosal surfaces, including airway and othersurfaces.

[0175] The active compounds disclosed herein may be administered tomucosal surfaces by any suitable means, including topically, orally,rectally, vaginally, ocularly and dermally, etc. For example, for thetreatment of constipation, the active compounds may be administeredorally or rectally to the gastrointestinal mucosal surface. The activecompound may be combined with a pharmaceutically acceptable carrier inany suitable form, such as sterile physiological or dilute saline ortopical solution, as a droplet, tablet or the like for oraladministration, as a suppository for rectal or genito-urethraladministration, etc. Excipients may be included in the formulation toenhance the solubility of the active compounds, as desired.

[0176] The active compounds disclosed herein may be administered to theairway surfaces of a patient by any suitable means, including as aspray, mist, or droplets of the active compounds in a pharmaceuticallyacceptable carrier such as physiological or dilute saline solutions ordistilled water. For example, the active compounds may be prepared asformulations and administered as described in U.S. Pat. No. 5,789,391 toJacobus, the disclosure of which is incorporated by reference herein inits entirety.

[0177] Solid or liquid particulate active agents prepared for practicingthe present invention could, as noted above, include particles ofrespirable or non-respirable size; that is, for respirable particles,particles of a size sufficiently small to pass through the mouth andlarynx upon inhalation and into the bronchi and alveoli of the lungs,and for non-respirable particles, particles sufficiently large to beretained in the nasal airway passages rather than pass through thelarynx and into the bronchi and alveoli of the lungs. In general,particles ranging from about 1 to 5 microns in size (more particularly,less than about 4.7 microns in size) are respirable. Particles ofnon-respirable size are greater than about 5 microns in size, up to thesize of visible droplets. Thus, for nasal administration, a particlesize in the range of 10-500 μm may be used to ensure retention in thenasal cavity.

[0178] In the manufacture of a formulation according to the invention,active agents or the physiologically acceptable salts or free basesthereof are typically admixed with, inter alia, an acceptable carrier.Of course, the carrier must be compatible with any other ingredients inthe formulation and must not be deleterious to the patient. The carriermust be solid or liquid, or both, and is preferably formulated with thecompound as a unit-dose formulation, for example, a capsule, that maycontain 0.5% to 99% by weight of the active compound. One or more activecompounds may be incorporated in the formulations of the invention,which formulations may be prepared by any of the well-known techniquesof pharmacy consisting essentially of admixing the components.

[0179] Compositions containing respirable or non-respirable dryparticles of micronized active agent may be prepared by grinding the dryactive agent with a mortar and pestle, and then passing the micronizedcomposition through a 400 mesh screen to break up or separate out largeagglomerates.

[0180] The particulate active agent composition may optionally contain adispersant which serves to facilitate the formulation of an aerosol. Asuitable dispersant is lactose, which may be blended with the activeagent in any suitable ratio (e.g., a 1 to 1 ratio by weight).

[0181] Active compounds disclosed herein may be administered to airwaysurfaces including the nasal passages, sinuses and lungs of a subject byan suitable means know in the art, such as by nose drops, mists., etc.In one embodiment of the invention, the active compounds of the presentinvention and administered by transbronchoscopic lavage. In a preferredembodiment of the invention, the active compounds of the presentinvention are deposited on lung airway surfaces by administering anaerosol suspension of respirable particles comprised of the activecompound, which the subject inhales. The respirable particles may beliquid or solid. Numerous inhalers for administering aerosol particlesto the lungs of a subject are known.

[0182] Inhalers such as those developed by Inhale Therapeutic Systems,Palo Alto, Calif., USA, may be employed, including but not limited tothose disclosed in U.S. Pat. Nos. 5,740,794; 5,654,007; 5,458,135;5,775,320; and 5,785,049. The Applicant specifically intends that thedisclosures of all patent references cited herein be incorporated byreference herein in their entirety. Inhalers such as those developed byDura Pharmaceuticals, Inc., San Diego, Calif., USA, may also beemployed, including but not limited to those disclosed in U.S. Pat. Nos.5,622,166; 5,577,497; 5,645,051; and 5,492,112. Additionally, inhalerssuch as those developed by Aradigm Corp., Hayward, Calif., USA, may beemployed, including but not limited to those disclosed in U.S. Pat. Nos.5,826,570; 5,813,397; 5,819,726; and 5,655,516. These apparatuses areparticularly suitable as dry particle inhalers.

[0183] Aerosols of liquid particles comprising the active compound maybe produced by any suitable means, such as with a pressure-drivenaerosol nebulizer or an ultrasonic nebulizer. See, e.g., U.S. Pat. No.4,501,729. Nebulizers are commercially available devices which transformsolutions or suspensions of the active ingredient into a therapeuticaerosol mist either by means of acceleration of compressed gas,typically air or oxygen, through a narrow venturi orifice or by means ofultrasonic agitation. Suitable formulations for use in nebulizersconsist of the active ingredient in a liquid carrier, the activeingredient comprising up to 40% w/w of the formulation, but preferablyless than 20% w/w. The carrier is typically water (and most preferablysterile, pyrogen-free water) or dilute aqueous alcoholic solution.Perfluorocarbon carriers may also be used. Optional additives includepreservatives if the formulation is not made sterile, for example,methyl hydroxybenzoate, antioxidants, flavoring agents, volatile oils,buffering agents and surfactants.

[0184] Aerosols of solid particles comprising the active compound maylikewise be produced with any solid particulate medicament aerosolgenerator. Aerosol generators for administering solid particulatemedicaments to a subject produce particles which are respirable, asexplained above, and generate a volume of aerosol containingpredetermined metered dose of medicament at a rate suitable for humanadministration. One illustrative type of solid particulate aerosolgenerator is an insufflator. Suitable formulations for administration byinsufflation include finely comminuted powders which may be delivered bymeans of an insufflator or taken into the nasal cavity in the manner ofa snuff. In the insufflator, the powder (e.g., a metered dose thereofeffective to carry out the treatments described herein) is contained incapsules or cartridges, typically made of gelatin or plastic, which areeither pierced or opened in situ and the powder delivered by air drawnthrough the device upon inhalation or by means of a manually-operatedpump. The powder employed in the insufflator consists either solely ofthe active ingredient or of powder blend comprising the activeingredient, a suitable powder diluent, such as lactose, and an optionalsurfactant. The active ingredient typically comprises of 0.1 to 100% w/wof the formulation. A second type of illustrative aerosol generatorcomprises a metered dose inhaler. Metered dose inhalers are pressurizedaerosol dispensers, typically containing a suspension or solutionformulation of active ingredient in a liquified propellant. During use,these devices discharge the formulation through a valve adapted todeliver a metered volume, typically from 10 to 150 μl, to produce a fineparticle spray containing the active ingredient. Suitable propellantsinclude certain chlorofluorocarbon compounds, for example,dichlorodifluoromethane, trichlorofluoromethane,dichlorotetrafluoroethane and mixtures thereof. The formulation mayadditionally contain one of more co-solvents, for example, ethanol,surfactants, such as oleic acid or sorbitan trioleate, antioxidants andsuitable flavoring agents.

[0185] The aerosol, whether formed from solid or liquid particles, maybe produced by the aerosol generator at a rate of from about 10 to 150liters per minute, more preferable from 30 to 150 liters per minute, andmost preferably about 60 liters per minute. Aerosols containing greateramounts of medicament may be administered more rapidly.

[0186] The dosage of the active compounds disclosed herein will varydepending on the condition being treated and the state of the subject,but generally may be from about 0.01, 0.03, 0.05, 0.1, 1, 5 to about 10or 20 mg of the pharmaceutic agent, deposited on the airway surfaces.The daily dose may be divided among one or multiple unit doseadministrations. The goal is to achieve a concentration of thepharmaceutic agents on lung airway surfaces of between 10⁻⁹-10⁴ M.

[0187] In another embodiment, they are administered by administering anaerosol suspension of respirable or non-respirable particles (preferablynon-respirable particles) comprised of active compound, which thesubject inhales through the nose. The respirable or non-respirableparticles may be liquid or solid. The quantity of active agent includedmay be an amount of sufficient to achieve dissolved concentrations ofactive agent on the airway surfaces of the subject of from about 10⁻⁹,10⁻⁸, or 10⁻⁷ to about 10⁻³, 10⁻², 10⁻¹ Moles/liter, and more preferablyfrom about 10⁻⁹ to about 10⁻⁴ Moles/liter.

[0188] The dosage of active compound will vary depending on thecondition being treated and the state of the subject, but generally maybe an amount sufficient to achieve dissolved concentrations of activecompound on the nasal airway surfaces of the subject from about 10⁻⁹,10⁻⁸, 10⁻⁷ to about 10⁻³, 10⁻², or 10⁻¹ Moles/liter, and more preferablyfrom about 10⁻⁷ to about 10⁻⁴ Moles/liter. Depending upon the solubilityof the particular formulation of active compound administered, the dailydose may be divided among one or several unit dose administrations. Thedaily dose by weight may range from about 0.01, 0.03, 0.1, 0.5 or 1.0 to10 or 20 milligrams of active agent particles for a human subject,depending upon the age and condition of the subject. A currentlypreferred unit dose is about 0.5 milligrams of active agent given at aregimen of 2-10 administrations per day. The dosage may be provided as aprepackaged unit by any suitable means (e.g., encapsulating a gelatincapsule).

[0189] In one embodiment of the invention, the particulate active agentcomposition may contain both a free base of active agent and apharmaceutically acceptable salt to provide both early release andsustained release of active agent for dissolution into the mucussecretions of the nose. Such a composition serves to provide both earlyrelief to the patient, and sustained relief over time. Sustained relief,by decreasing the number of daily administrations required, is expectedto increase patient compliance with course of active agent treatments.

[0190] Pharmaceutical formulations suitable for airway administrationinclude formulations of solutions, emulsions, suspensions and extracts.See generally, J. Nairn, Solutions, Emulsions, Suspensions and Extracts,in Remington: The Science and Practice of Pharmacy, chap. 86 (19^(th) ed1995). Pharmaceutical formulations suitable for nasal administration maybe prepared as described in U.S. Pat. No. 4,389,393 to Schor; U.S. Pat.No. 5,707,644 to Illum; U.S. Pat. No. 4,294,829 to Suzuki; and U.S. Pat.No. 4,835,142 to Suzuki; the disclosures of which are incorporated byreference herein in the entirety.

[0191] Mists or aerosols of liquid particles comprising the activecompound may be produced by any suitable means, such as by a simplenasal spray with the active agent in an aqueous pharmaceuticallyacceptable carrier, such as a sterile saline solution or sterile water.Administration may be with a pressure-driven aerosol nebulizer or anultrasonic nebulizer. See e.g. U.S. Pat. Nos. 4,501,729 and 5,656,256.Suitable formulations for use in a nasal droplet or spray bottle or innebulizers consist of the active ingredient in a liquid carrier, theactive ingredient comprising up to 40% w/w of the formulation, butpreferably less than 20% w/w. Typically the carrier is water (and mostpreferably sterile, pyrogen-free water) or dilute aqueous alcoholicsolution, preferably made in a 0.12% to 0.8% solution of sodiumchloride. Optional additives include preservatives if the formulation isnot made sterile, for example, methyl hydroxybenzoate, antioxidants,flavoring agents, volatile oils, buffering agents, osmotically activeagents (e.g. mannitol, xylitol, erythritol) and surfactants.

[0192] Compositions containing respirable or non-respirable dryparticles of micronized active agent may be prepared by grinding the dryactive agent with a mortar and pestle, and then passing the micronizedcomposition through a 400 mesh screen to break up or separate out largeagglomerates.

[0193] The particulate composition may optionally contain a dispersantwhich serves to facilitate the formation of an aerosol. A suitabledispersant is lactose, which may be blended with the active agent in anysuitable ratio (e.g., a 1 to 1 ratio by weight).

[0194] The compounds of formula (I) may be synthesized according toprocedures known in the art. A representative synthetic procedure isshown in the scheme below.

[0195] These procedures are described in, for example, E. J. Cragoe,“The Synthesis of Amiloride and Its Analogs” (Chapter 3) in Amilorideand Its Analogs, pp. 25-36, incorporated herein by reference. Othermethods of preparing the compounds are described in, for example, U.S.Pat. No. 3,313,813, incorporated herein by reference. See in particularMethods A, B, C, and D described in U.S. Pat. No. 3,313,813.

[0196] Several assays may be used to characterize the compounds of thepresent invention. Representative assays are discussed below.

[0197] In Vitro Measure of Sodium Channel Blocking Activity andReversibility

[0198] One assay used to assess mechanism of action and/or potency ofthe compounds of the present invention involves the determination oflumenal drug inhibition of airway epithelial sodium currents measuredunder short circuit current (I_(SC)) using airway epithelial monolayersmounted in Ussing chambers. Cells obtained from freshly excised human,dog, sheep or rodent airways are seeded onto porous 0.4 micron Snapwell™Inserts (CoStar), cultured at air-liquid interface (ALI) conditions inhormonally defined media, and assayed for sodium transport activity(I_(SC)) while bathed in Krebs Bicarbonate Ringer (KBR) in Usingchambers. All test drug additions are to the lumenal bath with half-logdose addition protocols (from 1×10⁻¹¹ M to 3×10⁻⁵M), and the cumulativechange in I_(SC) (inhibition) recorded. All drugs are prepared indimethyl sulfoxide as stock solutions at a concentration of 1×10⁻² M andstored at −20° C. Eight preparations are typically run in parallel; twopreparations per run incorporate amiloride and/or benzamil as positivecontrols. After the maximal concentration (5×10⁻⁵ M) is administered,the lumenal bath is exchanged three times with fresh drug-free KBRsolution, and the resultant I_(SC) measured after each wash forapproximately 5 minutes in duration. Reversibility is defined as thepercent return to the baseline value for sodium current after the thirdwash. All data from the voltage clamps are collected via a computerinterface and analyzed off-line.

[0199] Dose-effect relationships for all compounds are considered andanalyzed by the Prism 3.0 program. IC₅₀ values, maximal effectiveconcentrations, and reversibility are calculated and compared toamiloride and benzamil as positive controls.

[0200] Pharmacological Assays of Absorption

[0201] (1) Apical Disappearance Assay

[0202] Bronchial cells (dog, human, sheep, or rodent cells) are seededat a density of 0.25×10⁶/cm² on a porous Transwell-Col collagen-coatedmembrane with a growth area of 1.13 cm² grown at an air-liquid interfacein hormonally defined media that promotes a polarized epithelium. From12 to 20 days after development of an air-liquid interface (ALI) thecultures are expected to be >90% ciliated, and mucins will accumulate onthe cells. To ensure the integrity of primary airway epithelial cellpreparations, the transepithelial resistance (R_(t)) and transepithelialpotential differences (PD), which are indicators of the integrity ofpolarized nature of the culture, are measured. Human cell systems arepreferred for studies of rates of absorption from apical surfaces. Thedisappearance assay is conducted under conditions that mimic the “thin”films in vivo (˜25 μl) and is initiated by adding experimental sodiumchannel blockers or positive controls (amiloride, benzamil, phenamil) tothe apical surface at an initial concentration of 10 μM. A series ofsamples (5 μl volume per sample) is collected at various time points,including 0, 5, 20, 40, 90 and 240 minutes. Concentrations aredetermined by measuring intrinsic fluorescence of each sodium channelblocker using a Fluorocount Microplate Flourometer or HPLC. Quantitativeanalysis employs a standard curve generated from authentic referencestandard materials of known concentration and purity. Data analysis ofthe rate of disappearance is performed using nonlinear regression, onephase exponential decay (Prism V 3.0).

[0203] 2. Confocal Microscopy Assay of Amiloride Congener Uptake

[0204] Virtually all amiloride-like molecules fluoresce in theultraviolet range. This property of these molecules may be used todirectly measure cellular update using x-z confocal microscopy.Equimolar concentrations of experimental compounds and positive controlsincluding amiloride and compounds that demonstrate rapid uptake into thecellular compartment (benzamil and phenamil) are placed on the apicalsurface of airway cultures on the stage of the confocal microscope.Serial x-z images are obtained with time and the magnitude offluorescence accumulating in the cellular compartment is quantitated andplotted as a change in fluorescence versus time.

[0205] 3. In vitro Assays of Compound Metabolism

[0206] Airway epithelial cells have the capacity to metabolize drugsduring the process of transepithelial absorption. Further, although lesslikely, it is possible that drugs can be metabolized on airwayepithelial surfaces by specific ectoenzyme activities. Perhaps morelikely as an ecto-surface event, compounds may be metabolized by theinfected secretions that occupy the airway lumens of patients with lungdisease, e.g. cystic fibrosis. Thus, a series of assays is performed tocharacterize the compound metabolism that results from the interactionof test compounds with human airway epithelia and/or human airwayepithelial lumenal products.

[0207] In the first series of assays, the interaction of test compoundsin KBR as an “ASL” stimulant are applied to the apical surface of humanairway epithelial cells grown in the T-Col insert system. For mostcompounds, we test for metabolism (generation of new species) using highperformance liquid chromatography (HPLC) to resolve chemical species andthe endogenous fluorescence properties of these compounds to estimatethe relative quantities of test compound and novel metabolites. For atypical assay, a test solution (25 μl KBR, containing 10 μM testcompound) is placed on the epithelial lumenal surface. Sequential 5 to10 μl samples are obtained from the lumenal and serosal compartments forHPLC analysis of (1) the mass of test compound permeating from thelumenal to serosal bath and (2) the potential formation of metabolitesfrom the parent compound. In instances where the fluorescence propertiesof the test molecule are not adequate for such characterizations,radiolabeled compounds are used for these assays. From the HPLC data,the rate of disappearance and/or formation of novel metabolite compoundson the lumenal surface and the appearance of test compound and/or novelmetabolite in the basolateral solution is quantitated. The data relatingthe chromatographic mobility of potential novel metabolites withreference to the parent compound are also quantitated.

[0208] To analyze the potential metabolism of test compounds by CFsputum, a “representative” mixture of expectorated CF sputum obtainedfrom 10 CF patients (under IRB approval) has been collected. The sputumhas been be solubilized in a 1:5 mixture of KBR solution with vigorousvortexing, following which the mixture was split into a “neat” sputumaliquot and an aliquot subjected to ultracentrifugation so that a“supernatant” aliquot was obtained (neat=cellular; supernatant=liquidphase). Typical studies of compound metabolism by CF sputum involve theaddition of known masses of test compound to “neat” CF sputum andaliquots of CF sputum “supernatant” incubated at 37° C., followed bysequential sampling of aliquots from each sputum type forcharacterization of compound stability/metabolism by HPLC analysis asdescribed above. As above, analysis of compound disappearance, rates offormation of novel metabolities, and HPLC mobilities of novelmetabolites are then performed.

[0209] 4. Pharmacological Effects and Mechanism of Action of the Drug inAnimals

[0210] The effect of compounds for enhancing mucociliary clearance (MCC)can be measured using an in vivo model described by Sabater et al.,Journal of Applied Physiology, 1999, pp. 2191-2196, incorporated hereinby reference.

EXAMPLES

[0211] Having generally described this invention, a furtherunderstanding can be obtained by reference to certain specific exampleswhich are provided herein for purposes of illustration only and are notintended to be limiting unless otherwise specified.

[0212] Materials and methods. All reagents and solvents were purchasedfrom Aldrich Chemical Corp. and used without further purification. NMRspectra were obtained on either a Bruker WM 360 (¹H NMR at 360 MHZ and¹³C NMR at 90 MHZ) or a Bruker AC 300 (¹H NMR at 300 MHZ and ¹³C NMR at75 MHZ). Flash chromatography was performed on a Flash Elute™ systemfrom Elution Solution (PO Box 5147, Charlottesville, Va. 22905) chargedwith a 90 g silica gel cartridge (40M FSO-0110-040155, 32-63 μm) at 20psi (N₂). GC-analysis was performed on a Shimadzu GC-17 equipped with aHeliflex Capillary Column (Alltech); Phase: AT-1, Length: 10 meters, ID:0.53 mm, Film: 0.25 micrometers. GC Parameters: Injector at 320° C.,Detector at 320° C., FID gas flow: H₂ at 40 ml/min., Air at 400 ml/min.Carrier gas: Split Ratio 16:1, N₂ flow at 15 ml/min., N₂ velocity at 18cm/sec. The temperature program is 70° C. for 0-3 min, 70-300° C. from3-10 min, 300° C. from 10-15 min.

[0213] HPLC analysis was performed on a Gilson 322 Pump, detectorUV/Vis-156 at 360 nm, equipped with a Microsorb MV C8 column, 100 A, 25cm. Mobile phase: A=acetonitrile with 0.1% TFA, B=water with 0.1% TFA.Gradient program: 95:5 B:A for 1 min, then to 20:80 B:A over 7 min, thento 100% A over 1 min, followed by washout with 100% A for 11 min, flowrate: 1 ml/min.

Example 14-(4-hydroxyphenyl)butylamidino-3,5-diamino-6-chloropyrazinecarboxamidehydrochloride (V)

[0214] The title compound was prepared as shown in Scheme 1 below. The4-(4-hydroxyphenylbutyl)amine was prepared by routine organictransformations described in the following procedures. The coupling wasdone in accordance with the procedure described by Cragoe, E. J. Jr.,Oltersdorf, O. W. Jr. and delSolms. S. J. (1981) U.S. Pat. No.4,246,406, both incorporated herein by reference. The work up andpurification were modified in accordance with the physical properties ofV.

4-Methylphenylsulfonic acid 4-(4-methoxyphenyl)butyl ester (I)

[0215] Pyridine (15 mL) was added dropwise to a cooled (0° C.) solutionof 4-(4-methoxyphenyl)butanol (10.0 g, 0.055 mol) and p-toluenesulfonylchloride (13.6 g, 0.072 mol) in dry chloroform (100 mL) under stirring.The reaction mixture was stirred overnight at room temperature. Afterthis time, the reaction was quenched with 10% HCl (300 mL) and extractedwith chloroform. The organic fraction was washed with saturated NaHCO₃,water and dried over magnesium sulfate. The solvent was removed underreduced pressure and the residue purified by flash chromatography(eluent: hexane, ethyl acetate=15:1) to provide 12.9 g (66%) of I asclear oil. ¹H NMR (360 MHZ, CDCl₃) δ 1.61 (m, 4H), 2.44 (s, 3H), 2.52(m, 2H), 3.78 (s, 3H), 4.05 (m, 2H), 6.77 (d, J=12.5 Hz, 2H), 7.05 (d,J=12.5 Hz, 2H), 7.34 (d, J=10.5 Hz, 2H), 7.78 (d, J=10.5 Hz, 2H).

4-(4-Methoxyphenyl)butylazide (II)

[0216] Sodium azide (3.07 g, 0.047 mol) was added to a solution of II(12.9 g, 0.04 mol) in anhydrous DMF (70 mL) and the reaction mixture wasstirred 12 h at 80° C. (oil bath). Then solvent was removed at reducedpressure and the residual oil was treated with a mixture ofCH₂Cl₂:ether=3:1 (100 mL). The resulting solution was washed with water(2×100 mL), brine and dried over magnesium sulfate. The solvent wasremoved under reduced pressure and 7.6 g (95%) of II was obtained. Thepurity of II (99%) was determined by GC and TLC (eluent: hexane, ethylacetate=1:1), R_(f)=0.84.

4-(4-Methoxyphenyl)butylamine (III)

[0217] Lithium aluminum hydride (55 mL of a 1M solution in THF, 0.055mol) was added drop wise to a solution of II (7.6 g, 0.037 mol) in dryTHF (70 mL) at 0° C. and stirred overnight at room temperature in anargon atmosphere. The reaction mixture was treated with water (1.5 mL),then 15% NaOH (1.5 mL), then with more water (3 mL) and filtered. Thesolid precipitate was washed with THF. The combined organic fractionswere dried over magnesium sulfate and the solvent was removed underreduced pressure to give 6.2 g (94%) of III. The purity of III (99 %)was determined by GC. ¹H NMR (360 MHz, DMSO-d₆) δ 1.34 (m, 2H), 1.54 (m,2H), 2.51 (m, 4H), 3.70 (s, 3H), 6.83 (d, J=8.6 Hz, 2H), 7.08 (d, J=8.3Hz, 2H), ¹³C (90 MHz, DMSO-d₆) δ 28.6, 330, 34.1, 41.5, 54.8, 113.1,129.1, 132.2, 157.3

4-(4-Hydroxyphenyl)butylamine hydrobromide (IV)

[0218] Amine III (2.32 g, 0.012 mol) was stirred in boiling 48% HBr (50mL) for 3 h. After the reaction was completed, argon was bubbled throughthe solution and the solvent was evaporated under reduced pressure. Thesolid residue was dried above KOH to provide 3.1 g (90%) of IV. API MSm/z=166[C₁₀H₁₅NO+H]⁺

4-(4-Hydroxyphenyl)butylamidino-3,5-diamino-6-chloropyrazinecarboxamidehydrochloride (V)

[0219] 1-(3,5-Diamino-6-chloropyrazinoyl-2-methyl-pseudothioureahydroiodide (0.4 g, 1.03 mmol) was added to a suspension of4-(4-hydroxyphenyl)butylamine hydrobromide (IV) in a mixture of THF (35mL) and triethylamine (3 mL). The reaction mixture was stirred at refluxtemperature for 3 h, then the supernatant was separated and the solventwas removed under reduced pressure. The oily residue was washed withwater (2×30 mL), ether (3×30 mL) and then 10% HCl (40 mL) was added. Themixture was vigorously stirred for 10 min then the yellow solid wasfiltered off, dried and recrystallized twice from ethanol to give 181 mg(41%) of V as yellow solid. Purity is 98% by HPLC, retention time is9.77 min; ¹H NMR (300 MHz, DMSO-d₆) δ 1.56 (br s, 4H), 2.48 (br s, 2H),3.35 (m, 2H), 6.65 (d, J=8.5 Hz, 2H), 6.95 (d, J=8.6 Hz, 2H), 7.50 (brs, 2H), 8.75 (br s, 1H), 9.05 (br s, 1H), 9.33 (br s, 2H), 10.55 (s,1H); ¹³C NMR (75 MHz, CD₃OD) 28.7, 29.8, 35.4, 42.4, 111.2, 116.1,122.0, 130.0, 134.0, 155.0, 156.1, 156.8, 157.5, 167.0; APCI MS m/z=378[C₁₆H₂₀ClN₇O₂+H]⁺.

Example 24-(4-Hydroxyphenyl)butylamidino-3,5-diamino-6-chloropyrazinecarboxamidehydrochloride

[0220]

[0221] 4-Methylphenylsulfonic acid 4-(4-methoxyphenyl)butyl ester (1)

[0222] Pyridine (15 mL) was added drop wise to a cooled (0° C.) solutionof 4-(4-methoxyphenyl)butanol (10.0 g, 0.055 mol) and p-toluenesulfonylchloride (13.6 g, 0.072 mol) in dry chloroform (100 mL) under stirring.The reaction mixture was stirred overnight at room temperature. Afterthis time, the reaction was quenched with 10% HCl (300 mL) and extractedwith chloroform. The organic fraction was washed with saturated NaHCO₃,water and dried over magnesium sulfate. The solvent was removed underreduced pressure and the residue purified by flash chromatography(eluent: hexane/ethyl acetate 15:1) to provide 12.9 g (66%) of 1 asclear oil. ¹H NMR (360 MHz, CDCl₃) δ 1.61 (m, 4H), 2.44 (s, 3H), 2.52(m, 2H), 3.78 (s, 3H), 4.05 (m, 2), 6.77 (d, 2H), 7.05 (d, 2H), 7.34 (d,2H), 7.78 (d, 2H).

4-(4-Methoxyphenyl)butylazide (2)

[0223] Sodium azide (3.07 g, 0.047 mol) was added to a solution of 1(12.9 g, 0.04 mol) in anhydrous DMF (70 mL) and the reaction mixture wasstirred 12 h at 80° C. (oil bath). Then solvent was removed at reducedpressure and the residual oil was treated with a mixture of CH₂Cl₂/ether3:1 (100 mL). The resulting solution was washed with water (2×100 mL),brine and dried over magnesium sulfate. The solvent was removed underreduced pressure and 7.6 g (95%) of 2 was obtained. The purity of 2(99%) was determined by GC and TLC (eluent: hexane/ethyl acetate 1:1),R_(f)=0.84.

4-(4-Methoxyphenyl)butylamine (3). Typical procedure A

[0224] Lithium aluminum hydride (LAH) (55 mL of a 1.0 M solution in THF,0.055 mol) was added drop wise to a solution of 2 (7.6 g, 0.037 mol) indry THF (70 mL) at 0° C. The mixture was stirred overnight at roomtemperature in an argon atmosphere then the mixture was treated withwater (1.5 mL), then 15% NaOH (1.5 mL), then with more water (3 mL) andfiltered. The solid precipitate was washed with THF. The combinedorganic fractions were dried over magnesium sulfate and the solvent wasremoved under reduced pressure to give 6.2 g (94%) of 3. The purity of 3(99%) was determined by GC. ¹H NMR (360 MHz, DMSO-d₆) δ 1.34 (m, 2H),1.54 (m, 2H), 2.51 (m, 4H), 3.70 (s, 3H), 6.83 (d, 2H), 7.08 (d, 2H).¹³C (90 MHz, DMSO-d₆) δ 28.6, 330, 34.1, 41.5, 54.8, 113.1, 129.1,132.2, 157.3

4-(4-Hydroxyphenyl)butylamine hydrobromide (4). Typical procedure B

[0225] Amine 3 (2.32 g, 0.012 mol) was stirred in boiling 48% HBr (50mL) for 3 h. After the reaction was completed, argon was bubbled throughthe solution and the solvent was evaporated under reduced pressure. Thesolid residue was dried above KOH to provide 3.1 g (90%) of 4. APCI MSm/z=166[C₁₀H₁₅NO+H]⁺

4-(4-Hydroxyphenyl)butylamidino-3,5-diamino-6-chloropyrazinecarboxamidehydrochloride (5)

[0226] 1-(3,5-Diamino-6-chloropyrazinoyl-2-methyl-pseudothioureahydroiodide (0.4 g, 1.03 mmol) was added to a suspension of4-(4-hydroxyphenyl)butylamine hydrobromide (4) (0.8 g, 32 mmol) in amixture of THF (35 mL) and triethylamine (3 mL). The reaction mixturewas stirred in the boiling solvent for 3 h, then the supernatant wasseparated and the solvent was removed under reduced pressure. The oilyresidue was washed with water (2×30 mL), ether (3×30 mL) and then 10%HCl (40 mL) was added. The mixture was vigorously stirred for 10 minthen the yellow solid was filtered off, dried and recrystallized twicefrom ethanol to give 5 (0.18 g, 41%) as yellow solid. Purity is 98% byHPLC, retention time is 9.77 min. ¹H NMR (300 MHz, DMSO-d₆) δ 1.56 (brs, 4H), 2.48 (br s, 2H), 3.35 (m, 2H), 6.65 (d, 2H), 6.95 (d, 2H), 7.50(br s, 2H), 8.75 (br s, 1H), 9.05 (br s, 1H), 9.33 (br s, 2H), 10.55 (s,1H). ¹³C NMR (75 MHz, CD₃OD) 28.7, 29.8, 35.4, 42.4, 111.2, 116.1,122.0, 130.0, 134.0, 155.0, 156.1, 156.8, 157.5, 167.0. APCI MS m/z=378[C₁₆H₂₀ClN₇O₂+H]⁺.

Example 33-(4-Hydroxyphenyl)propylamidino-3,5-diamino-6-chloropyrazinecarboxamidehydrochloride

[0227]

[0228] Methanesulfonic acid 3-(4-methoxyphenyl)propyl ester (11).Typical procedure E. Pyridine (15 mL) was added drop wise to a cooled(0° C.) solution of 4-(4-methoxyphenyl)propanol (10.0 g, 0.06 mol) andmethanesulfonyl chloride (14.7 g, 0.078 mol) in dry THF (70 mL) understirring. The reaction mixture was stirred overnight at roomtemperature. After this time, the solvent was removed under reducedpressure and the residue was quenched with 10% HCl (300 mL) andextracted with ethyl acetate. The organic fraction was washed withsaturated NaHCO₃, water and dried over sodium sulfate. The solvent wasremoved and the residual crude ester 11 was used in the next stepwithout further purification. Compound 11 was obtained as a yellow oil(8.8 g, 60%). ¹H NMR (300 MHz, CDCl₃) δ 2.08 (m, 2H), 2.60 (m, 2H), 2.98(m, 2H) 3.98 (s, 3H), 3.66 (s, 3H), 6.85 (d, 2H), 7.03 (d, 2H).

3-(4-Methoxyphenyl)propylazide (12)

[0229] Azide 12 was prepared according to procedure C from 11 (8.8 g,0.036 mol) and sodium azide (3 g, 0.045 mol) in 75% yield. ¹H NMR (300MHz, CDCl₃) δ 1.90 (m, 2H), 2.65 (t, 2H), 3.28 (m, 2H), 3.80 (s, 3H),6.85 (d, 2H), 7.10 (d, 2H).

3-(4-Methoxyphenyl)propylamine (13)

[0230] Amine 13 was prepared as described in procedure A from azide 12(5.2 g, 0.027 mol) and LAH (26 ml of 1 M solution in THF).

[0231] Crude 13 was purified by flash chromatography (silica gel,2:1:0.05 chloroform/ethanol/concentrated ammonium hydroxide) to providepure amine 13 (3.2 g, 74%) as a clear oil. ¹H NMR (300 MHz, CDCl₃) δ1.58 (m, 2H), 2.50 (m, 4H), 3.72 (s, 3H), 6.85 (d, 2H), 7.10 (d, 2H).

3-(4-Hydroxyphenyl)propylamine hydrobromide (14)

[0232] Compound 14 was synthesized according to procedure B from 13 (2.5g, 0.015 mol) in 75% yield as a light brown solid. ¹H NMR (300 MHz,DMSO-d₆) δ 1.80 (m, 2H), 2.53 (m, 2H), 2.78 (m, 2H), 6.70 (d, 2H), 7.02(d, 2H), 7.80 (br s, 4H).

3-(4-Hydroxyphenyl)propylamidino-3,5-diamino-6-chloropyrazinecarboxamidehydrochloride (15)

[0233] Triethylamine (8 mL) was added to suspension of compound 14(0.470 g, 2 mmol) in THF (40 mL) and the mixture was stirred at roomtemperature for 15 min. After this time1-(3,5-diamino-6-chloropyrazinoyl-2-methyl-pseudothiourea hydroiodide(0.15 g, 0.4 mmol) was added and the mixture was stirred at reflux for 3h. The solution was then cooled to room temperature and the supernatantwas isolated. The solvent was evaporated and the residual oil was washedwith ether (2×50 mL), ethyl acetate (50 mL) and treated with 20 ml of10% HCl. The obtained solid was isolated by filtration and dissolved inMeOH (approx. 50 mL). Addition of ethyl acetate (20 mL) to the solutioncaused the precipitation of a yellow solid, which was isolated bycentrifugation, washed with ethyl acetate and dried under vacuum to givecompound 15 (48 mg, 31%) as a yellow solid. ¹H NMR (300 MHz, DMSO-d₆) δ1.80 (br s, 2H), 2.58 (m, 2H), 3.95 (br s, 4H), 6.70 (d, 2H), 7.03 (d,2H), 7.48 (br. s, 2H), 8.80 (br s, 1H), 8.93 (br s, 1H), 9.32 (br s,2H), 10.52 (s, 1H). APCI MS m/z=364 [C₁₅H₁₈ClN₇O₂+H]⁺.

Example 45-(4-Hydroxyphenyl)pentylamidino-3,5-diamino-6-chloropyrazinecarboxamidehydrochloride

[0234]

5-(4-Methoxyphenyl)pent-4-yn-1-ol (16)

[0235] 4-Iodoanisol (10 g, 42 mmol), palladium (II) chloride (0.2 g, 1.1mmol) and triphenylphosphine (0.6 g, 2.2 mmol) were dissolved indiethylamine (100 mL) then cupper(I) iodide (0.5 g, 2.2 mmol) and4-pentyn-1-ol (5 mL, 53 mmol) were added. The reaction mixture wasstirred overnight at room temperature, then the solvent was removedunder reduced pressure. Ethyl acetate (150 mL) was added to the residueand the mixture was washed with 2N HCl, brine and water. The organicfraction was isolated, dried with sodium sulfate and the solvent wasremoved under reduced pressure. The product 16 (7.1 g. 87%) was isolatedby flash chromatography (silica gel, 1:2 ethyl acetate/hexanes) as anoily yellow solid. ¹H NMR (300 MHz, CDCl₃) δ 1.88 (m, 2H), 2.53 (m, 2H),3.72 (s, 3H), 3.74 (m, 2H), 6.83 (d, 2H), 7.45 (d, 2H).

5-(4-Methoxyphenyl)pentane-1-ol (17)

[0236] A solution of 16 (7.1 g, 37 mmol) in 150 dry ethanol (150 mL) wasplaced in a 0.5 L Parr flask and palladium on carbon (0.92 g, 5% wet.Pd/C) was added as a suspension in ethanol (25 mL). The reaction mixturewas shaken at 50 psi of hydrogen pressure at room temperature for 24hours. After this time, the mixture was filtered through a silica gelpad and the solvent was removed at reduced pressure. The residue waspurified by flash chromatography (silica gel, 1:3 ethyl acetate/hexanes)to provide 17 (6.7 g, 92%) as a clear oil. ¹H NMR (300 MHz, CDCl₃) δ1.48 (m, 2H), 1.60 (m, 4H), 2.58 (m, 2H), 3.63 (m, 2H) 3.80 (s, 3H),6.83 (d, 2H), 7.10 (d, 2H).

Methanesulfonic acid 4-(4-methoxyphenyl)pentyl ester (18)

[0237] Ester 18 was prepared following procedure E from alcohol 17 (6.7g, 34.5 mmol) and methanesulfonyl chloride (4.5 mL, 50 mmol). The crudeproduct 18 (9.0 g) was obtained as a brown oil and used in the next stepwithout purification.

5-(4-Methoxyphenyl)pentyl azide (19)

[0238] Compound 19 was synthesized according to procedure C from crude18 (9.0 g) and sodium azide (2.7 g, 40 mmol). Azide 19 (6 g, 79% from17) was isolated by flash chromatography (silica gel, 1:1 ethylacetate/hexanes). ¹H NMR (300 MHz, CDCl₃) δ 1.40 (m, 2H), 1.62 (m, 4H),2.56 (m, 2H), 3.35 (m, 2H) 3.80 (s, 3H), 6.85 (d, 2H), 7.10 (d, 2H).

5-(4-Methoxyphenyl)pentyl amine (20)

[0239] Amine 20 was made following procedure A from 19 (6 g, 27 mmol)and LAH (26 mL of 1.0M solution in THF) in 70% yield. ¹H NMR (300 MHz,CDCl₃) δ 1.35(m, 2H), 1.48 (m, 2H) 1.61 (m, 2H), 2.55 (m, 2H), 2.70 (m,2H) 3.80 (s, 3H), 6.85 (d, 2H), 7.10 (d, 2H).

5-(4-Hydroxyphenyl)pentyl amine (21)

[0240] The HBr salt of 21 was prepared according to procedure B fromamine 20 (2.8 g, 14 mmol). Free amine 21 (2 g, 80%) was obtained afterflash chromatography (silica gel, 6:3:0.1,chloroform/ethanol/concentrated ammonium hydroxide) as a cloudy oil. ¹HNMR (300 MHz, DMSO-d₆) δ 1.28(m, 2H), 1.55 (m, 2H), 1.61 (m, 2H), 2.48(m, 2H), 2.58 (m, 2H), 6.68 (d, 2H), 6.98 (d, 2H).

5-(4-Hydroxyphenyl)pentylamidino-3,5-diamino-6-chloropyrazinecarboxamidehydrochloride (22)

[0241] 1-(3,5-Diamino-6-chloropyrazinoyl-2-methyl-pseudothioureahydroiodide (0.25 g, 0.65 mmol) was added to a solution of 21 (0.6 g,3.4 mmol) in THF (50 mL). The reaction mixture was stirred at reflux for2 h, then the solvent was removed under reduced pressure and theresulting oil was washed with ether (2×50 mL) and treated with ethylacetate until a yellow powder was formed. The yellow solid was dissolvedin methanol (70 mL) and the volume was slowly reduced untilprecipitation began (approximately 25 mL). The solution was cooled to 0°C. and the precipitate was collected by centrifugation. Diluted HCl (20mL of a 10% solution) was added and the mixture was vigorously stirredfor 20 min, then the precipitate was filtered off, washed with coldwater, and dried to give 22 (183 mg, 39%) as a yellow solid. ¹H NMR (300MHz, DMSO-d₆) δ 1.32 (br s, 2H), 1.55 (m, 4H), 2.45 (m, 2H), 3.29 (m,2H), 6.68 (d, 2H), 6.97 (d, 2H), 7.46 (s, 1H), 8.00 (br s, 1H), 8.83 (brs, 1H), 8.97 (br s, 1H), 9.46 (d, 2H), 10.55 (s, 1H). APCI MSm/z=392[C₁₇H₂₂ClN₇O₂+H]⁺.

Example 54-(3,4-Dihydroxyphenyl)butylamidino-3,5-diamino-6-chloropyrazinecarboxamidehydrochloride

[0242]

4-(3,4-Dimethoxyphenyl)butanol (23)

[0243] 4-(3,4-Dimethoxyphenyl)butyric acid (13 g, 58 mmol) was dissolvedin dry THF (150 mL) then BH₃.THF (110 mL, 1M solution, 110 mmol) wasadded drop wise with vigorous stirring under an argon atmosphere. Thereaction mixture was then stirred overnight at room temperature. Afterthis time, the reaction was quenched with water and 10% HCl solution at0° C. and extracted with ethyl acetate. The organic fraction was driedwith sodium sulfate and passed through a pad of silica gel. The solventwas removed at reduced pressure to give 23 (12.0 g, 99%) as a clear oil.¹H NMR (300 MHz, CDCl₃) δ 1.62 (m, 4H), 2.0 (s, 1H), 2.62 (m, 2H), 3.65(m, 2H), 3.82 (s, 3H), 3.84 (s, 3H) 6.67-6.82 (m, 3H).

Methanesulfonic acid 4-(3,4-dimethoxyphenyl)butyl ester (24)

[0244] Ester 24 was prepared following procedure E from alcohol 23 (12.0g, 57 mmol) and methanesulfonyl chloride (8.4 g, 74 mmol) in 78% yield.¹H NMR (300 MHz, CDCl₃) δ 1.65 (m, 4H), 2.62 (m, 2H),3.05 (s, 3H), 3.88(br s, 6H), 4.38 (m, 2H) 6.70-6.88 (m, 3H).

4-(3,4-Dimethoxyphenyl)butyl azide (25)

[0245] Compound 25 was synthesized according to procedure C from 24(14.1 g 51 mmol) and sodium azide (4.0 g, 66 mmol) in 96% yield. ¹H NMR(300 MHz, CDCl₃) δ 1.65 (m, 4H), 2.60 (m, 2H), 3.30 (m, 2H), 3.86 (br s,6H), 6.70 (m, 2H), 6.78 (m, 1H).

4-(3,4-Dimetoxyphenyl)butyl amine (26)

[0246] Amine 26 was prepared as described in procedure A from azide 25(11.0 g, 49 mol) and LAH (26 mL of 1 M solution in THF). Crude 26 waspurified by flash chromatography (silica gel, 93:7:1chloroform/ethanol/concentrated ammonium hydroxide) to give pure 26 (4.8g, 42%) as a clear oil. ¹H NMR (300 MHz, CDCl₃) δ 1.42(m, 2H), 1.60 (m,2H), 2.55 (m, 2H), 2.74 (m, 2H), 3.82 (s, 6H), 3.84 (s, 3H), 6.70 (m,2H), 6.78 (m, 1H).

4-(3,4-Dihydroxyphenyl)butyl amine hydrobromide (27)

[0247] Compound 27 was synthesized according to procedure B from 26 (2.5g, 11 mmol) in 62% yield as a pink solid. ¹H NMR (300 MHz, DMSO-d₆) δ1.52 (br s, 4H), 2.40 (m, 2H), 2.78 (m, 2H), 6.42 (m, 1H), 6.60 (m, 2H),7.80 (br s, 4H).

4-(3,4-Dihydroxyphenyl)butylamidino-3,5-diamino-6-chloropyrazinecarboxamidehydrochloride (28)

[0248] 1-(3,5-Diamino-6-chloropyrazinoyl-2-methyl-pseudothioureahydroiodide (0.2 g, 0.51 mmol) was added to a suspension of 27 in amixture of THF (35 mL) and triethylamine (3 mL). The reaction mixturewas stirred at reflux for 3 h, then the supernatant was separated andthe solvent was removed under reduced pressure. The brown residue waswashed with ether (2×30 mL) followed by addition of 10% HCl (5 mL). Thesolid material was collected, dissolved in methanol and precipitated byaddition of ethyl acetate. The precipitate was washed with 10% HCl anddried to give compound 28 (131 mg, 51%) as a beige solid. ¹H NMR (300MHz, DMSO-d₆) δ 1.52 (br s, 4H), 2.42 (m, 2H), 3.31 (m, 2H), 6.43 (m,1H), 6.61 (m, 2H), 7.42 (br s, 2H), 7.90 (br s, 1H), 8.82 (br s, 1H),8.98 (br s, 1H), 9.25 (s, 1H) 10.52 (s, 1H). APCI MS m/z=394[C₁₆H₂₀ClN₇O₃+H]⁺.

Example 64-(4-Hydroxyphenyl)-4-oxabutylamidino-3,5-diamino-6-chloropyrazinecarboxamidehydrobromide

[0249]

4-(4-Hydroxyphenyl)-4-oxabutylamidino-3,5-diamino-6-chloropyrazinecarboxamidehydrobromide (63)

[0250] The vigorously stirred solution of 62 (80 mg, 0.19 mmol) in 48%HBr (15 mL) was refluxed 2 h and then cooled. The precipitate thatformed was separated, washed with water and dried overnight to provide63 (52 mg, 52%). ¹H NMR (300 MHz, DMSO-d₆) δ 1.99 (m, 2H), 3.96 (m, 2H),6.77 (m, 2H), 6.79 (m, 2H), 7.45 (s, 2H), 8.74 (br s, 1H), 8.87 (br s,1H), 9.30 (s, 1H) 10.48 (s, 1H). APCI MS m/z 380 [C₁₅H₁₈ClN₇O₃+H]⁺.

Example 74-(2,4-Dihydroxyphenyl)butylamidino-3,5-diamino-6-chloropyrazinecarboxamidehydrochloride

[0251]

4-(2,4-Dimethoxyphenyl)-but-3-yn-1-ol (75)

[0252] 1-Bromo-2,4-dimethoxybenzene (10 g 0.046 mol), palladium chloride(0.2 g 0.11 mmol) and triphenylphosphine (0.6 g 0.0023 mol) weredissolved in diethylamine (100 mL) under a nitrogen atmosphere. Copper(I) iodide (0.44 g 0.0023 mol) and 3-butyn-1-ol (7 mL 0.092 mol) wereadded into the reaction mixture at once. The mixture was stirredovernight at 55° C. under a nitrogen atmosphere. The catalyst wasfiltered off from the reaction mixture and the same amount of palladiumchloride, triphenylphosphine, copper (I) iodide and 3-butyn-1-ol wereadded. The reaction mixture was stirred and heated at 85° C. for 48hours. Then the solvent was removed at reduced pressure and water(approx. 100 mL) was added to the residue. The mixture was extractedwith ethyl acetate (350 mL) passed through a pad of silica gel andconcentrated. The product was purified by flash chromatography (silicagel, 1:1 hexanes/ethyl acetate). Compound 75 (4.2 g, 24%) was isolatedas a brown oil. ¹H NMR (300 MHz, CDCl₃) δ 2.24 (t, 1H), 2.73 (t, 2H),3.80 (br s, 5H), 3.87 (s, 3H), 6.43 (m, 2H), 7.30 (m, 1H).

4-(2,4-Dimethoxyphenyl)-butan-1-ol (76)

[0253] To a solution of 75 (4.2 g, 0.022 mol) in ethanol (approx. 200mL) was added palladium (5% wet on activated carbon, 1 g). Then themixture was hydrogenated at 40 psi overnight at room temperature. Themixture was filtered through a pad of silica gel and the solvent wasevaporated to give 76 (4.15 g, 97%) as a yellow oil. ¹H NMR (300 MHz,CDCl₃) δ 1.59 (m, 4H), 2.55 (m, 2H), 3.79 (s, 6H), 6.43 (m, 2H), 7.00(m, 1H).

Methanesulfonic acid 4-(2,4-dimethoxyphenyl)butyl ester (77)

[0254] Ester 77 was prepared by typical procedure E from alcohol 76(4.15 g, 0.021 mol), methanesulfonyl chloride (2.4 mL, 0.03 mol) andtriethylamine (20 mL). Crude 77 (4.6 g, 80%) was isolated as a yellowoil

4-(2,4-Dimethoxyphenyl)butyl azide (78)

[0255] Azide 78 was prepared by typical procedure C from ester 77 (4.6g, 0.015 mol) and sodium azide (1.5 g, 0.023 mol). Compound 77 (4.06 g,75%) was isolated as a yellow oil. ¹H NMR (300 MHz, CDCl₃) δ 1.62 (m,4H), 2.58 (m, 2H), 3.30 (m, 2H), 3.80 (s, 6H), 6.43 (m, 2H), 7.00 (m,1H).

4-(2,4-Dimethoxyphenyl)butyl amine (79)

[0256] Amine 79 was prepared by typical procedure A from azide 78 (4.06g, 0.017 mol) and LiAlH₄ (13 mL of a 1.0 M solution in THF). Thematerial was purified by column chromatography (silica gel, 2:1:0.1chloroform/ethanol/concentrated ammonium hydroxide) to provide 79 (2.3g, 64%) as a white solid. ¹H NMR (300 MHz, CDCl₃) δ 1.53 (m, 4H), 2.53(m, 2H), 2.73 (m, 2H), 3.80 (s, 6H), 6.43 (m, 2H), 7.52 (m, 1H).

4-(2,4-Dimethoxyphenyl)butylamidino-3,5-diamino-6-chloropyrazinecarboxamide hydrochloride (80)

[0257] 1-(3,5-Diamino-6-chloropyrazinoyl-2-methyl-pseudothioureahydroiodide (0.3 g, 0.77 mmol) was added to an anhydrous THF solution(30 mL) of 79 (0.4 g, 1.9 mmol). The reaction mixture was stirred atreflux for 3 h then the solvent was evaporated. The residue was washedwith ethyl acetate (2×20 mL) then treated with 3% HCl (15 mL). Theyellow solid that formed was separated, washed with water and driedovernight to provide compound 80 (0.32 g, 90%). ¹H NMR (300 MHz,DMSO-d₆) δ 1.57 (s, 4H), 2.50 (br s, 2H), 3.35 (br s, 2H), 3.73 (s, 3H),3.76 (s, 3H), 6.43 (m, 1H), 6.52 (s, 1H), 7.02 (m, 1H), 7.45 (br s, 2H),8.86 (br s, 1H), 8.99 (br s, 1H), 9.03 (m, 1H), 10.56 (s, 1H). APCI MSm/z 422 [C₁₈H₂₄ClN₇O₃+H]⁺.

4-(2,4-Dihydroxyphenyl)butylamidino-3,5-diamino-6-chloropyrazinecarboxamide hydrochloride (81)

[0258] A vigorously stirred solution of 80 (290 mg, 0.63 mmol) in 48%HBr (20 mL) was refluxed for 4 h and then cooled. The solvent wasremoved at reduced pressure and the material was purified by columnchromatography (silica gel, 4:1:0.1 chloroform/ethanol/concentratedammonium hydroxide). The fractions with product were collected and thesolvent was removed under reduced pressure. The residue was treated with3% HCl, washed with water (2×5 mL) and dried to provide 81 (79 mg, 32%)as a yellow solid. ¹H NMR (300 MHz, DMSO-d₆) δ 1.54 (s, 4H), 2.43 (br s,2H), 3.31 (br s, 2H), 6.12 (d, 1H), 6.32 (s, 1H), 6.78 (d, 1H), 8.86 (brs, 1H), 8.99 (br s, 1H), 9.28 (s, 1H), 10.56 (s, 1H). APCI MS m/z 394[C₁₆H₂₀ClN₇O₃+H]⁺.

[0259] References:

[0260] 1. Taylor, E. C.; Harrington, P. M.; Schin, C. Heterocycles,1989, 28, 1169

[0261] 2. Widsheis et al, Synthesis, 1994, 87-92

Example 8 Sodium Channel Blocking Activity

[0262] The compounds shown in Tables 1-5 below were tested for potencyin canine bronchial epithelia using the in vitro assay described above.Amiloride was also tested in this assay as a positive control. Theresults for the compounds of the present invention are reported asfold-enhancement values relative to amiloride. TABLE 1

Fold Enhancement Position R Over Amiloride 2,4 H 14.9 3,5 H 13.7 3,4 H15.1 2,5 H 20.3

[0263] TABLE 2

Position Fold Enhancement n of R R Over Amiloride 5 4 OH 14 3 4 OH 5.2 44 OH 50.3

[0264] TABLE 3

Fold Enhancement Q R Over Amiloride N OH 9.5 CH OH 50.3

[0265] TABLE 4

Fold Enhancement a b R Over Amiloride CH₂ O H 16.1

Example 9 Effect of4-(4-hydroxyphenyl)butylamidino-3,5-diamino-6-chloropyrazinecarboxamidehydrochloride (V) on MCC

[0266] This experiment was conducted with4-(4-hydroxyphenyl)butylamidino-3,5-diamino-6-chloropyrazinecarboxamidehydrochloride (V), and the vehicle as a control. The results are shownin FIGS. 1 and 2.

[0267] Methods

[0268] Animal Preparation: The Mount Sinai Animal Research Committeeapproved all procedures for the in vivo assessment of mucociliaryclearance. Adult ewes (ranging in weight from 25 to 35 kg) wererestrained in an upright position in a specialized body harness adaptedto a modified shopping cart. The animals' heads were immobilized andlocal anesthesia of the nasal passage was induced with 2% lidocaine. Theanimals were then nasally intubated with a 7.5 mm internal diameterendotracheal tube (ETT). The cuff of the ETT was placed just below thevocal cords and its position was verified with a flexible bronchoscope.After intubation the animals were allowed to equilibrate forapproximately 20 minutes prior to initiating measurements of mucociliaryclearance.

[0269] Administration of Radio-aerosol: Aerosols of ^(99m)Tc-Human serumalbumin (3.1 mg/ml; containing approximately 20 mCi) were generatedusing a Raindrop Nebulizer which produces a droplet with a medianaerodynamic diameter of 3.6 μm. The nebulizer was connected to adosimetry system consisting of a solenoid valve and a source ofcompressed air (20 psi). The output of the nebulizer was directed into aplastic T connector; one end of which was connected to the endotrachealtube, the other was connected to a piston respirator. The system wasactivated for one second at the onset of the respirator's inspiratorycycle. The respirator was set at a tidal volume of 500 mL, aninspiratory to expiratory ratio of 1:1, and at a rate of 20 breaths perminute to maximize the central airway deposition. The sheep breathed theradio-labeled aerosol for 5 minutes. A gamma camera was used to measurethe clearance of ^(99m)Tc-Human serum albumin from the airways. Thecamera was positioned above the animal's back with the sheep in anatural upright position supported in a cart so that the field of imagewas perpendicular to the animal's spinal cord. External radio-labeledmarkers were placed on the sheep to ensure proper alignment under thegamma camera. All images were stored in a computer integrated with thegamma camera. A region of interest was traced over the imagecorresponding to the right lung of the sheep and the counts wererecorded. The counts were corrected for decay and expressed aspercentage of radioactivity present in the initial baseline image. Theleft lung was excluded from the analysis because its outlines aresuperimposed over the stomach and counts can be swallowed radio-labeledmucus.

[0270] Treatment Protocol (Assessment of activity at t-zero): A baselinedeposition image was obtained immediately after radio-aerosoladministration. At time zero, after acquisition of the baseline image,vehicle control (distilled water), positive control (amiloride), orexperimental compounds were aerosolized from a 4 ml volume using a PariLC JetPlus nebulizer to free-breathing animals. The nebulizer was drivenby compressed air with a flow of 8 liters per minute. The time todeliver the solution was 10 to 12 minutes. Animals were extubatedimmediately following delivery of the total dose in order to preventfalse elevations in counts caused by aspiration of excess radio-tracerfrom the ETT. Serial images of the lung were obtained at 15-minuteintervals during the first 2 hours after dosing and hourly for the next6 hours after dosing for a total observation period of 8 hours. Awashout period of at least 7 days separated dosing sessions withdifferent experimental agents.

[0271] Treatment Protocol (Assessment of Activity at t-4 hours): Thefollowing variation of the standard protocol was used to assess thedurability of response following a single exposure to vehicle control(distilled water), positive control compounds (amiloride or benzamil),or investigational agents. At time zero, vehicle control (distilledwater), positive control (amiloride), or investigational compounds wereaerosolized from a 4 ml volume using a Pari LC JetPlus nebulizer tofree-breathing animals. The nebulizer was driven by compressed air witha flow of 8 liters per minute. The time to deliver the solution was 10to 12 minutes. Animals were restrained in an upright position in aspecialized body harness for 4 hours. At the end of the 4-hour periodanimals received a single dose of aerosolized ^(99m)Tc-Human serumalbumin (3.1 mg/ml; containing approximately 20 mCi) from a RaindropNebulizer. Animals were extubated immediately following delivery of thetotal dose of radio-tracer. A baseline deposition image was obtainedimmediately after radio-aerosol administration. Serial images of thelung were obtained at 15-minute intervals during the first 2 hours afteradministration of the radio-tracer (representing hours 4 through 6 afterdrug administration) and hourly for the next 2 hours after dosing for atotal observation period of 4 hours. A washout period of at least 7 daysseparated dosing sessions with different experimental agents.

[0272] Statistics: Data were analyzed using SYSTAT for Windows, version5. Data were analyzed using a two-way repeated ANOVA (to assess overeffects), followed by a paried t-test to identify differences betweenspecific pairs. Significance was accepted when P was less than or equalto 0.05. Slope values (calculated from data collected during the initial45 minutes after dosing in the t-zero assessment) for mean MCC curveswere calculated using linear least square regression to assessdifferences in the initial rates during the rapid clearance phase.

[0273] Obviously, numerous modifications and variations of the presentinvention are possible in light of the above teachings. It is thereforeto be understood that within the scope of the appended claims, theinvention may be practiced otherwise than as specifically describedherein.

[0274] All of the references cited above are incorporated herein byreference.

1-81. (canceled)
 82. A compound represented by formula (I):

wherein X is hydrogen, halogen, trifluoromethyl, lower alkyl,unsubstituted or substituted phenyl, lower alkyl-thio, phenyl-loweralkyl-thio, lower alkyl-sulfonyl, or phenyl-lower alkyl-sulfonyl; Y ishydrogen, hydroxyl, mercapto, lower alkoxy, lower alkyl-thio, halogen,lower alkyl, unsubstituted or substituted mononuclear aryl, or —N(R²)₂;R¹ is hydrogen or lower alkyl; each R² is, independently, —R⁷,—(CH₂)_(m)—OR⁸, —(CH₂)_(m)—NR⁷R¹⁰, —(CH₂)_(n)(CHOR⁸)(CHOR⁸)_(n)—CH₂OR⁸,—(CH₂CH₂O)_(m)—R⁸, —(CH₂CH₂O)_(m)—CH₂CH₂NR⁷R¹⁰, —(CH₂)_(n)—C(═O)NR⁷R¹⁰,—(CH₂)_(n)-Z_(g)-R⁷, —(CH₂)_(m)—NR¹⁰—CH₂(CHOR⁸)(CHOR⁸)_(n)—CH₂OR⁸,—(CH₂)_(n)—CO₂R⁷, or

R³ and R⁴ are each, independently, hydrogen, a group represented byformula (A), lower alkyl, hydroxy lower alkyl, phenyl, phenyl-loweralkyl, (halophenyl)-lower alkyl, lower-(alkylphenylalkyl), loweralkoxyphenyl)-lower alkyl, naphthyl-lower alkyl, or pyridyl-lower alkyl,with the proviso that at least one of R³ and R⁴ is a group representedby formula (A):

wherein each R^(L) is, independently, —R⁷, —(CH₂)_(n)—OR⁸,—O—(CH₂)_(m)—OR⁸, —(CH₂)_(n)—NR⁷R¹⁰, —O—(CH₂)_(m)—NR⁷R¹⁰,—(CH₂)_(n)(CHOR⁸)(CHOR⁸)_(n)—CH₂OR⁸,—O—(CH₂)_(m)(CHOR⁸)(CHOR⁸)_(n)—CH₂OR⁸, —(CH₂CH₂O)_(m)—R⁸,—O—(CH₂CH₂O)_(m)—R⁸, —(CH₂CH₂O)_(m)—CH₂CH₂NR⁷R¹⁰,—O—(CH₂CH₂O)_(m)—CH₂CH₂NR⁷R¹⁰, —(CH₂)_(n)—C(═O)NR⁷R¹⁰,—O—(CH₂)_(m)—C(═O)NR⁷R¹⁰, —(CH₂)_(n)-(Z)_(g)-R⁷,—O—(CH₂)_(m)-(Z)_(g)-R⁷, —(CH₂)_(n)—NR¹⁰—CH₂(CHOR⁸)(CHOR⁸)_(n)—CH₂OR⁸,—O—(CH₂)_(m)—NR¹⁰—CH₂(CHOR⁸)(CHOR⁸)_(n)—CH₂OR⁸, —(CH₂)_(n)—CO₂R⁷,—O—(CH₂)_(m)—CO₂R⁷, —OSO₃H, —O-glucuronide, —O-glucose, or

each x represents a single bond; each o is, independently, an integerfrom 0 to 10; each p is, independently, an integer from 0 to 10; the sumof o and p is 4; each R⁶ is, independently, hydrogen; each R⁷ is,independently, hydrogen or lower alkyl; each R⁸ is, independently,hydrogen, lower alkyl, —C(═O)—R¹¹, glucuronide, 2-tetrahydropyranyl, or

each R⁹ is, independently, —CO₂R⁷, —CON(R⁷)₂, —SO₂CH₃, or —C(═O)R⁷; eachR¹⁰ is, independently, —H, —SO₂CH₃, —CO₂R⁷, —C(═O)NR⁷R⁹, —C(═O)R⁷, or—CH₂—(CHOH)_(n)—CH₂OH; each Z is, independently, CHOH, C(═O), CHNR⁷R¹⁰,C═NR¹⁰, or NR¹⁰; each R¹¹ is, independently, lower alkyl; each g is,independently, an integer from 1 to 6; each m is, independently, aninteger from 1 to 7; each n is, independently, an integer from 0 to 7;each Q is, independently, C—R⁶; or a pharmaceutically acceptable saltthereof, and inclusive of all enantiomers, diastereomers, and racemicmixtures thereof.
 83. The compound of claim 82, wherein Y is —NH₂. 84.The compound of claim 83, wherein R² is hydrogen.
 85. The compound ofclaim 84, wherein R¹ is hydrogen.
 86. The compound of claim 85, whereinX is chlorine.
 87. The compound of claim 86, wherein R³ is hydrogen. 88.The compound of claim 87, wherein each R^(L) is hydrogen.
 89. Thecompound of claim 82, wherein X is halogen; Y is —N(R⁷)₂; R¹ is hydrogenor C₁-C₃ alkyl; and R² is —R⁷, —(CH₂)_(m)—OR⁷, or —(CH₂)_(n)—CO₂R⁷; R³isa group represented by formula (A); and R⁴ is hydrogen, a grouprepresented by formula (A), or lower alkyl.
 90. The compound of claim89, wherein X is chloro or bromo; Y is —N(R⁷)₂; R² is hydrogen or C₁-C₃alkyl; at most three R⁶ are other than hydrogen as defined above; and atmost three R^(L) are other than hydrogen as defined above.
 91. Thecompound of claim 90, wherein Y is —NH₂.
 92. The compound of claim 91,wherein R⁴ is hydrogen; at most one R^(L) is other than hydrogen asdefined above.
 93. The compound of claim 82, wherein each R^(L) ishydrogen.
 94. The compound of claim 82, wherein at most two R^(L) areother than hydrogen as defined in claim
 1. 95. The compound of claim 82,wherein one R^(L) is other than hydrogen as defined in claim
 1. 96. Thecompound of claim 82, which is represented by the formula


97. The compound of claim 82, which is in the form of a pharmaceuticallyacceptable salt.
 98. The compound of claim 82, which is in the form of ahydrochloride salt.
 99. The compound of claim 82, which is in the formof a mesylate salt.
 100. A pharmaceutical composition, comprising thecompound of claim 82 and a pharmaceutically acceptable carrier.
 101. Acomposition, comprising: the compound of claim 82; and a P2Y2 inhibitor.102. A composition, comprising: the compound of claim 82; and abronchodilator.
 103. A method of blocking sodium channels, comprisingcontacting sodium channels with an effective amount of the compound ofclaim 82.